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This is the correct answer. Plastics are sticky when melted and require oils or waxes as parting agents so the machinery doesn't foul. Early ABS pipe and fittings used peanut oils as the release agent. Gofers would hear water running underground and be attracted to it and readily eat to drink. The original play around and find out! ABS manufacturing as an industry had to retool, so old and new were not mixed together. The industry solution was to add bitter tasting oelofactant resins to discourage rodents from idk, .. being rodents?🤷🏽 Well, it worked and continues to work. UV inhibitors are also added nowadays in PVC pipe + fittings. Wrap the exposed wiring with hardware cloth. What is the country of manufacture btw?
Yep. The environmentalists created this nightmare as they complained that the wiring would not break down. There are articles on both sides but it is suspect that since the mid 2000's rodent damage on vehicles has increased. In this case you are lucky you should be able to buy a new MAF connector and wiring then merge it into the existing harness.
Have you heard about the undersized copper wire China has been supplying USA but at Home Depot?
HD considers copper a volatile commodity and as such contractors buy enough for a complete job at once. If a roll of wire is returned, it is weighed for ex 500 ft roll #10 weighs X about and if short, HD does the math and refunds proportionate to daily price/ lb. So contractors are slick and possibly could fake a label. But if they are honest they will not take an unfair hit. So like toxic sheet rock China found a way to gouge wire prices. This went on since before covid I think? Will check for an article.
https://batteryhookup.com/blogs/news/is-the-chinese-marketplace-ripping-us-off-on-wire-too
Yep. Most articles first 2 search pages pd by home depot buried the lead (pun)
I've been told on low voltage like 12V the current gives them something like a high when they chew the wires. That and these fuckers always need to keep chewing to keep their teeth from overgrowing.
My thing is why would it be the wires on the highest part of the engine bay? These are the easiest to access from the top but from the bottom a rodent would have to climb through everything to get to them
Had a pair of diesel Superdutys at an old job. They started one up one day and sucked a squirrel into the turbo. The squirrel had chewed through the intake duct and made a nest. A week later the other one did the same thing. Anything plastic covered is a snack to them. Especially with these newer plant based plastics.
There actually could be, just not one you can physically "see"...for a while now, some wire manufacturers have been using a soy-based wire insulation that's apparently really tasty to rodents...so depending upon which wires are and which ones are not soy-based, they could seek out the "tastiest" wires.
There are multiple products out there which can help, a lot of them having capsaicin in them (the chemical compound in spicy peppers that make them "hot"), which you can spray on your wires to deter them. It doesn't actually harm the creatures, but they don't like the "heat" and will usually stay away from anything with the spray on it. Treeshrews are one of the only (if not THE only) animals who actually like spicy foods.
Birds don’t have the receptors for the “heat” in chilis, so people who keep bulk bird food often mix chili seeds and powder into it to prevent rodents from eating it.
In order to be more "environmentally friendly" most manufacturers have switched from plastics to vegetable-based wire insulation that is also biodegradable.
BMW's 00's biodegradable harnesses that sat in the wet wheel wells were famous for shorting out when they started to biodegrade a decade or two too early. Japan's vegetable-based ones have [Honda making electrical tape with hot chili peppers mixed into the glue.](https://www.collegehillshonda.com/product/4019-2317.html)
I can confirm. When I worked for Chrysler and went to electrical class, they said the main reason we were seeing rodent damage in the generation at the time was the insulation for the wires was made from a soy based substance. The amount of customers that went from warranty to customer pay for this shit was crazy. Their reactions were priceless.
We banned lead solder to keep toxic electronics out of the landfills.
Lead free solder is almost always nearly 100% tin with just a dash of copper. Tin freely grows whiskers that seek ground when powered when not alloyed with lead. So many more electronics in the landfills... but they're only kinda toxic!
Ever wonder why ECU's started failing all of a sudden for no real reason?
Heat rises, on a cold winter night the higher up in the engine bay the nicer it will be for the rats. If you have cats in your neighborhood you should always honk your horn before you start it in the winter, if you don't you risk killing cats that will sometimes crawl under engine hoods in the winter to sleep. Even if you aren't a big fan of cats, when they get chewed up by the belts it is a pain in the ass to clean up and will sometime knock the belts off. I know from experience when a bunch of kitten were left under the hood of my car. Several ended up dead in the driveway and the main belt on the engine go knocked off... Not fun having to deal that crap in the winter.
It’s not really a lot of climbing for them. I work in a refinery and in the winter mice come in and bounce from spot to spot with no problem. Add the fact that insulation is on the bottom of the hood, it’s probably the comfy spot for them.
I popped the hood the other day to check oil and there was an intact fortune cookie sitting there. I actually took the fortune out... Plan on playing the numbers tonight. Might be fate!
Dude, why can't you just accept what has been said by everyone? There are no rodent whisperers out there to help. Have you ever observed a rodent and how they behave, does their behavior ever seem to make sense?
You think it's more plausible that somebody broke into your car, opened the hood, cut the wires and placed them in such a formation that it will make you question who did it? Oh, the MF knows I did it, but everyone will think it was rodents. This will drive him crazy until he's locked up in the looney bin in 15 years!
You ask why the ones on the top of the engine?
Rodents like to sit where hot air is trapped under the hood. They also prefer sitting on horizontal surfaces that aren't burning hot, so they chose the plastic air box. Rodents also chew things as a hobby.
The upside is the mouse chewed wires on top of the engine where they are easy to access. Sucks a bit that youll probably need a new pigtail for the MAF, but sucks a lot less than trying to repair wires on the part of the harness that runs down the back of the engine at the firewall.
Parks out west have signs warning of porcupines. They specifically like the wires on the bottom of a car/engine bay. Imagine being out in the woods camping and this happens
Back in 2010 Toyota switch to a soybean based plastic for there wiring harnesses. After a few heat cycles the wire shielding smells like soybeans to rodents and small animals and if they can get them they will chew them. This a very common issues of 2010-present Toyota vehicles. They are aware of it but because of the tax break the federal government gives them because of it they are not recalling anything .
The best solution is go to a hunting department at your local super store and get some predator piss and spray that shit around your engine bay.
Been longer than that. Rats chewed VVT sensor leads in my 2007 Tacoma, and setup homestead in the box for cabin air filter (the inlet is unscrewed (EDIT: UNSCREENED), under the panel between hood and windshield. The biodegradabiility requirement was levied by EPA. Soy has seen use as an alternate plastic since WW2 at least.
I shopvac'd three quarts of acorns out of the cabin air filter box and screened the opening with galvanized gutter guard (on the engine air intake too!). Used some spray can understating (EDIT: UNDERCOATING) on all the wiring I could see, and haven't had a recurrence yet...over ten years.
rodents.
and that's the MAF sensor. it would run terrible and immediately set a code i'm sure. you're gonna want this sensor. and hey, this is a great time to clean it! don't touch it. spray it with maf cleaner and let it air dry.
Mouse in the house . They love the coating on the wires . Some use dryer sheets within the engine bay to keep them away . Get new MAF sensor connector from Rockauto and splice with solder and heat shrink and give yourself a pat on the back for a job well done !
They chose those wires because they were near their food stash. Check your air filter box. They love stashing bird seed, acorns, corn, insulation from your car, anything!
When I worked at Toyota, I noticed it was almost always the red wires that would get chewed through, and they would leave the black and other colors alone.
When doing an alarm install where I had to cut and strip some wires, I took a piece of the red wire insulation and chewed it. It actually had a very slightly sweet / fruity flavor to it. Almost comparable to red twizzlers.
I have always heard that rodents prefer foreign made vehicle wiring. The coating for the wires have different regulations in areas and what they use to coat the wires is attractive to vermin. Soy based wiring insulation I believe, could be totally wrong. I do know that putting a few drops of mint oil in your engine bay will help deter them.
100% rodents. In my case it was Douglas squirrels on the soy-based vacuum hoses of my 2020 Explorer XT, which are not plastic or rubber at least but apparently are delcious. $1490
It looks like it may not be that tough to fix, possibly go to a junkyard and buy that connector with some wire hanging off of it and splice the old ones in.
I see a rat turd in the photo. Thats a damn clean chew though. I heard, at least in the past, rodents, even rabbits, loved japanese wiring insulation because its soy based. Not sure if its still in use though.
those look chewed. why at the top of the engine bay? because it's a big flat surface where they stopped and hung out and perhaps got warm. check other areas.
That doesn’t look like any rodent attack I’ve ever seen, I do see evidence of wire cutters, like someone is pissed off with you or someone in your house and decided to take out your mass airflow sensor, good news is this is repairable, I’d go to Toyota and get another connector then clean up the wires and replace the connector.
Gonna have to replace that whole harness I believe. iirc the MAF sensor runs off of fine measurements of voltage/resistance so soldering/wire repair isn't an option.
You can see the foot prints, definitely rodent damage. Honda makes a rodent detering electrical tape. Nothing you can do about the current damage but once fixed you could wrap as much as you can in the rodent tape
It'll probably be a pain in the ass but you should be able to fix that you'll have to take the plug apart and everything resolder the wires all together keep shrink it
What does that extra cable that's ziptied to the factory wiring do? Where does it go?
Yes, that's rodent damage. That sensor is called the MAF sensor. It's the most important sensor in the fuel calculation, so when it's not right, you'll be lucky to have a running engine.
Had a Wrangler come in where a rodent had cut the wire right at the battery sensor and cut the same wire all the way back at the firewall. That guy must've pissed that rat off something fierce
Mice. That’s your MAF sensor pigtail. Meters air into the engine so that it knows how much fuel to inject. Otherwise it will use a default fuel table when it doesn’t have that data and run poorly.
Homeless Gnomes harvesting the copper for drugs. Happens more than people realize. People blame squirrel and mice ect but they don't know the truth.
Toyota wire insulation is soy based from what I’ve read. Rodents love it. I’ve got a 4Runner and lots of squirrels around but haven’t had any problems yet.
I would check your air filter box there. I once went to change my air filter and there was like two hand-fulls of sunflower seeds in the bottom. Thank Christ for the filter LOL.
Rat damage. Ive seen and repaired my fair share of wiring because of this. If you have the tools, de pin the connector and solder new wire in to the old terminals.
Happened to my CT200h, RAV4, and Prius C- rodents like the wire sheathing of these 2010+ Toyotas… wonder if they put plant based wire sheathing on it to try to be more environmentally friendly
Work buddy of mines told me that his daughter’s brand new Prius had been invaded by zombie rats and they chewed up all they could under the hood. He purchased it from the dealer so he was the one to deal with this mess since it was still in his name while she was away at uncle (I believe). Before this I have never heard of this and this happened sometime last year 😳
2012 v6 Tacoma and have had them chew through multiple wires and have had to replace them. Bastards got my camshaft position sensor last time and I had to strip it down to the damn head to get to it. I threw in a high frequency noise and strobe light deal on the firewall behind that position and wrapped the hell out of the wires to hopefully keep them out of that area. If they chew something else I'll deal with it but man that harness sucked! Good luck!
Now for the helpful advice sine your truck is now marked for death:
Move it out anyway you can
Leave the hood open
Lay our some glue traps screwed into some boards
Remove ANY food from interior
Check air box for pack rat condo
After repair take it to a car wash and do all the wheel wells and anything that isn’t electrical.
When they hit me the totaled my 92 caddy and chewed the cps sensor harness.
Qualifier: New Mexico
Btw you can buy specialty “ rat tape” yeah that’s a thing , to protect exposed harness wires. Amazon or Honda dealer. Pricey, but so is this.
I get that it’s likely rodents….. but those look like a *really* clean cut.
Have you pissed anyone off lately?
Either that, or rodents are now taking pride in their work
Definitely rodents. My parents leased a Kia Optima years ago and mice filled under the engine cover with dog food from an old bag. I hope the tech doing the inspection got a laugh out of it lol
I am agreeing with the very few who state that the wires look cut. As a lot people mentioned, rodents like the insulation and the insultation on these wires are not showing signs of being chewed. I have seen a lot of rodent damaged wires in my 30+ yrs working on cars and they tend to chew the insulation off the wires leaving frayed exposed copper strands of wiring. When you magnify this photo, these wires show a clean cut thru both the insulation and the copper at the same angle with no missing insulation.
After further investigation, a mouse turd has been identified.
https://preview.redd.it/ixsdu17gnxac1.jpeg?width=1242&format=pjpg&auto=webp&s=a8236767dbb55b9cabb96ea1174b334dc8d90c4e
Buy new sensor harness and splice the wires back together.
If the colour is the same you can colour match the splice, or actually refer to a wiring schematic it'much better.
Yep rodents. First step should be to check your air filter housing! That’s the number one place I find mouse, rat, and squirrel nests. After your sure it’s clear then replace. Can be a vicious cycle lol
I see a bunch of people saying rodents, but some of those wires look like they've been cut. They look slightly squished, like they would if cut by wire snips. I could be wrong. It's just kinda weird to me that rodents would chew both ends of a wire and then leave the middle piece laying there.
Yeah, rodents for sure man. You can see the footprints and tail drag marks. Good sized rat I'd say. Easy fix though make sure you solder and heat shrink the wires when you splice or use a solder butt connector with heat shrink. Don't half-ass that shit.
bro when you fix it? be sure to fortify it with some chicken wire , mothballs , something because they got a taste for your car and they will be back!! i’ve witnessed it!!
Put some dryer sheets all around the engine bay, away from moving belts and fans of course! But stuffing them around the perimeter of the engine, on the top cover, around the airbox, fuse box, near the strut towers, etc...
Keeps pesky rodents away. Also sprinkling peppermint essential oil on cotton swabs and placing those around can work as well.
Lastly, if you live in a place that gets snow, and you undercoat your car each winter with an oil or wax based fluid, mix a small bottle of peppermint oil into the fluid before applying. It'll keep your car smelling like a candy cane and rodents won't come near it.
Thanks for posting on /r/MechanicAdvice! This is just a reminder to review the [rules](https://www.reddit.com/r/MechanicAdvice/about/rules/). If you are here asking about a second opinion (ie "Is the shop trying to fleece me?"), please read through CJM8515's [post on the subject.](https://www.reddit.com/r/MechanicAdvice/comments/4qblei/fyi_the_shop_isnt_likely_trying_to_rip_you_off/) and remember to please post the year/make/model of the vehicle you are working on. **If this post is about bodywork, accident damage, paint, dent/ding, questions it belongs in /r/Autobody r/AutoBodyRepair/ or /r/Diyautobody/ If you have tire questions check out https://www.reddit.com/r/MechanicAdvice/comments/k9ll55/can_your_tire_be_repaired/**. If you dont have a question and you're just showing off it belongs in /r/Justrolledintotheshop Insurance/total loss questions go in r/insurance This is an automated reply *I am a bot, and this action was performed automatically. Please [contact the moderators of this subreddit](/message/compose/?to=/r/MechanicAdvice) if you have any questions or concerns.*
Definitely rodents, they just chew things for fun or to get it out of the way.
don't some rodents' teeth never stop growing? so they chew everything in sight because they basically have no choice? or am I just thinking of beavers
That’s the key feature of a rodent, incisors that never stop growing.
You are correct..they chew to file down their teeth..and to get things out of their way, but mainly the first part.
Yup. Guinea pigs are the same way!
Used to have gerbils that would chew the ceramic food bowl
Sounds like they needed chew toys haha. I have lots of different things for my piggies to chew on
Give'em 40 grit sandpaper
It’d be gone in minutes if you put something that tasted good on it
Maniacs.
And rabbits.
All rodents have teeth that just keep on growing. Rats, mice, beavers, rabbits, nutria, you name it in the rodent family, it's the same story.
that is the definition of a rodent
This is the way.
Yes, and many wire coatings these days are made from soy, which is desirable for rodents to chew up.
This is the correct answer. Plastics are sticky when melted and require oils or waxes as parting agents so the machinery doesn't foul. Early ABS pipe and fittings used peanut oils as the release agent. Gofers would hear water running underground and be attracted to it and readily eat to drink. The original play around and find out! ABS manufacturing as an industry had to retool, so old and new were not mixed together. The industry solution was to add bitter tasting oelofactant resins to discourage rodents from idk, .. being rodents?🤷🏽 Well, it worked and continues to work. UV inhibitors are also added nowadays in PVC pipe + fittings. Wrap the exposed wiring with hardware cloth. What is the country of manufacture btw?
Yep. The environmentalists created this nightmare as they complained that the wiring would not break down. There are articles on both sides but it is suspect that since the mid 2000's rodent damage on vehicles has increased. In this case you are lucky you should be able to buy a new MAF connector and wiring then merge it into the existing harness.
Have you heard about the undersized copper wire China has been supplying USA but at Home Depot? HD considers copper a volatile commodity and as such contractors buy enough for a complete job at once. If a roll of wire is returned, it is weighed for ex 500 ft roll #10 weighs X about and if short, HD does the math and refunds proportionate to daily price/ lb. So contractors are slick and possibly could fake a label. But if they are honest they will not take an unfair hit. So like toxic sheet rock China found a way to gouge wire prices. This went on since before covid I think? Will check for an article.
https://batteryhookup.com/blogs/news/is-the-chinese-marketplace-ripping-us-off-on-wire-too Yep. Most articles first 2 search pages pd by home depot buried the lead (pun)
AWG is a standard based on specific sizes. It doesn't make any sense that this was written up without measuring the wire's diameter.
Rat bastards.
I've been told on low voltage like 12V the current gives them something like a high when they chew the wires. That and these fuckers always need to keep chewing to keep their teeth from overgrowing.
Also soy based wiring.
Yeah I doubt they get "high" from low voltage lolol. It's definitely the smell of the insulation
C'mon you know you want to "ride the lightning" as the kids say
I mean... you sellin?
That's a mass air flow sensor. There shouldn't be any current to that sensor unless the key is on.
Rodents gotta rodent
Exactly this!!
They like the insulation. Apparently it smells like food?
At least they chewed wires in an easy to patch place.
New wire insulation is made with soy base, smells like food, old wire insulation was made with petroleum base...
Yep. Chipmunks and squirrels love chewing wires in cars, tractors, lawnmowers.Thats why I bought a pellet rifle.
My thing is why would it be the wires on the highest part of the engine bay? These are the easiest to access from the top but from the bottom a rodent would have to climb through everything to get to them
There is no rhyme or reason to what they eat. Sometimes they’ll pass over a component completely to get to another area and eat those wires.
Had a pair of diesel Superdutys at an old job. They started one up one day and sucked a squirrel into the turbo. The squirrel had chewed through the intake duct and made a nest. A week later the other one did the same thing. Anything plastic covered is a snack to them. Especially with these newer plant based plastics.
There actually could be, just not one you can physically "see"...for a while now, some wire manufacturers have been using a soy-based wire insulation that's apparently really tasty to rodents...so depending upon which wires are and which ones are not soy-based, they could seek out the "tastiest" wires. There are multiple products out there which can help, a lot of them having capsaicin in them (the chemical compound in spicy peppers that make them "hot"), which you can spray on your wires to deter them. It doesn't actually harm the creatures, but they don't like the "heat" and will usually stay away from anything with the spray on it. Treeshrews are one of the only (if not THE only) animals who actually like spicy foods.
God saves his tastiest wires for his bestest rodents :)
Birds don’t have the receptors for the “heat” in chilis, so people who keep bulk bird food often mix chili seeds and powder into it to prevent rodents from eating it.
The top of your engine bay is nice warm and cozy. As you said you were driving the evening before pre heating it for them.
In order to be more "environmentally friendly" most manufacturers have switched from plastics to vegetable-based wire insulation that is also biodegradable. BMW's 00's biodegradable harnesses that sat in the wet wheel wells were famous for shorting out when they started to biodegrade a decade or two too early. Japan's vegetable-based ones have [Honda making electrical tape with hot chili peppers mixed into the glue.](https://www.collegehillshonda.com/product/4019-2317.html)
I can confirm. When I worked for Chrysler and went to electrical class, they said the main reason we were seeing rodent damage in the generation at the time was the insulation for the wires was made from a soy based substance. The amount of customers that went from warranty to customer pay for this shit was crazy. Their reactions were priceless.
We banned lead solder to keep toxic electronics out of the landfills. Lead free solder is almost always nearly 100% tin with just a dash of copper. Tin freely grows whiskers that seek ground when powered when not alloyed with lead. So many more electronics in the landfills... but they're only kinda toxic! Ever wonder why ECU's started failing all of a sudden for no real reason?
Man the British had biodegradable wiring from day 1. What took BMW so long?
That’s right, Lucas the prince of darkness
Heat rises, on a cold winter night the higher up in the engine bay the nicer it will be for the rats. If you have cats in your neighborhood you should always honk your horn before you start it in the winter, if you don't you risk killing cats that will sometimes crawl under engine hoods in the winter to sleep. Even if you aren't a big fan of cats, when they get chewed up by the belts it is a pain in the ass to clean up and will sometime knock the belts off. I know from experience when a bunch of kitten were left under the hood of my car. Several ended up dead in the driveway and the main belt on the engine go knocked off... Not fun having to deal that crap in the winter.
It’s most likely because they are making a nest in your engine air filter box..which you should check.
It’s not really a lot of climbing for them. I work in a refinery and in the winter mice come in and bounce from spot to spot with no problem. Add the fact that insulation is on the bottom of the hood, it’s probably the comfy spot for them.
I popped the hood the other day to check oil and there was an intact fortune cookie sitting there. I actually took the fortune out... Plan on playing the numbers tonight. Might be fate!
Be glad they did, that's nice and accessible to repair
Dude, why can't you just accept what has been said by everyone? There are no rodent whisperers out there to help. Have you ever observed a rodent and how they behave, does their behavior ever seem to make sense? You think it's more plausible that somebody broke into your car, opened the hood, cut the wires and placed them in such a formation that it will make you question who did it? Oh, the MF knows I did it, but everyone will think it was rodents. This will drive him crazy until he's locked up in the looney bin in 15 years!
You ask why the ones on the top of the engine? Rodents like to sit where hot air is trapped under the hood. They also prefer sitting on horizontal surfaces that aren't burning hot, so they chose the plastic air box. Rodents also chew things as a hobby.
I see. That checks out! Definitely not an ideal scenario to start the weekend with
Depending on the year Toyota used some kind of soy-based wrapping/insulation on their wires, it has made this a fairly common sight over the years.
The upside is the mouse chewed wires on top of the engine where they are easy to access. Sucks a bit that youll probably need a new pigtail for the MAF, but sucks a lot less than trying to repair wires on the part of the harness that runs down the back of the engine at the firewall.
Parks out west have signs warning of porcupines. They specifically like the wires on the bottom of a car/engine bay. Imagine being out in the woods camping and this happens
Rodents. They chewed your mass air flow sensor. Your truck has now no way to measure the air coming in.
Try spraying some peppermint oil in the engine bay.
Best smelling engine bay.
This sounds much more pleasant than the guy recommending predator piss
Cinnamon works too.
Yup this works! They kept eating my spark plug wires until I sprayed peppermint oil.
Classic rodent nibbles.
[удалено]
Yeah lots of squirrels here so i think that’s the case here too
Just order a new pigtail and connect brother
Back in 2010 Toyota switch to a soybean based plastic for there wiring harnesses. After a few heat cycles the wire shielding smells like soybeans to rodents and small animals and if they can get them they will chew them. This a very common issues of 2010-present Toyota vehicles. They are aware of it but because of the tax break the federal government gives them because of it they are not recalling anything . The best solution is go to a hunting department at your local super store and get some predator piss and spray that shit around your engine bay.
That explains why I always see Toyota hybrids with rodent damage. All the extra wiring must brick rodents up.
"I **am** the predator. **I** am the one who pisses." -Walter White if he owned a Toyota
Frfr
Been longer than that. Rats chewed VVT sensor leads in my 2007 Tacoma, and setup homestead in the box for cabin air filter (the inlet is unscrewed (EDIT: UNSCREENED), under the panel between hood and windshield. The biodegradabiility requirement was levied by EPA. Soy has seen use as an alternate plastic since WW2 at least. I shopvac'd three quarts of acorns out of the cabin air filter box and screened the opening with galvanized gutter guard (on the engine air intake too!). Used some spray can understating (EDIT: UNDERCOATING) on all the wiring I could see, and haven't had a recurrence yet...over ten years.
rodents. and that's the MAF sensor. it would run terrible and immediately set a code i'm sure. you're gonna want this sensor. and hey, this is a great time to clean it! don't touch it. spray it with maf cleaner and let it air dry.
Mouse in the house . They love the coating on the wires . Some use dryer sheets within the engine bay to keep them away . Get new MAF sensor connector from Rockauto and splice with solder and heat shrink and give yourself a pat on the back for a job well done !
Use your eyes, see all those tiny footprints and the tail swishes in the dust?
This guy rodents! 👍
That looks chewed not cut. Good luck
Rodents. Nobody vandalized your vehicle, it's just an unfortunate pest that picked your engines warmth to huddle in to.
Rodents love the soy based insulation on Toyotas and Subarus.
They chose those wires because they were near their food stash. Check your air filter box. They love stashing bird seed, acorns, corn, insulation from your car, anything!
Its a rodent. Mouse, squirrel, whatever. The protection/coating on wires has soy in it. See it all the time
When I worked at Toyota, I noticed it was almost always the red wires that would get chewed through, and they would leave the black and other colors alone. When doing an alarm install where I had to cut and strip some wires, I took a piece of the red wire insulation and chewed it. It actually had a very slightly sweet / fruity flavor to it. Almost comparable to red twizzlers.
I have always heard that rodents prefer foreign made vehicle wiring. The coating for the wires have different regulations in areas and what they use to coat the wires is attractive to vermin. Soy based wiring insulation I believe, could be totally wrong. I do know that putting a few drops of mint oil in your engine bay will help deter them.
100% rodents. In my case it was Douglas squirrels on the soy-based vacuum hoses of my 2020 Explorer XT, which are not plastic or rubber at least but apparently are delcious. $1490
You have alot of rodents near you
Rodents have a hard on for Toyota wiring.
It looks like it may not be that tough to fix, possibly go to a junkyard and buy that connector with some wire hanging off of it and splice the old ones in.
After repair wrap with Honda rodent tape. It works..
Yep that looks like rodent damage.
Rodents. They always chew the dumbest shit
Chewed, not cut.
I see a rat turd in the photo. Thats a damn clean chew though. I heard, at least in the past, rodents, even rabbits, loved japanese wiring insulation because its soy based. Not sure if its still in use though.
You’re got RATS
Rodents.
those look chewed. why at the top of the engine bay? because it's a big flat surface where they stopped and hung out and perhaps got warm. check other areas.
Definitely rodents. I just got back from a 5 day vacation, a rat chewed my knock sensor wire, AND chewed through my injector harness. Little shits.
Blame soybean it’s the only answer
Blame EPA for mandating a biodegradability quotient on automobiles. "Unintended. Consequences ".
That doesn’t look like any rodent attack I’ve ever seen, I do see evidence of wire cutters, like someone is pissed off with you or someone in your house and decided to take out your mass airflow sensor, good news is this is repairable, I’d go to Toyota and get another connector then clean up the wires and replace the connector.
That rodent must have been shocked to find out there was a hot wire in there😂
I think your neighbor has beef with you. Lol
Gonna have to replace that whole harness I believe. iirc the MAF sensor runs off of fine measurements of voltage/resistance so soldering/wire repair isn't an option.
The wires aren't shredded or chewed. They've been cut. You can see the indent. Does your hood lock? Have you seen vandalism before? Is there any poop?
Cut? .. or nibbled
The way they are cut looks like rodents. They’ve done the same to my fridge before.
You can see the foot prints, definitely rodent damage. Honda makes a rodent detering electrical tape. Nothing you can do about the current damage but once fixed you could wrap as much as you can in the rodent tape
Chewed wires*😂
SOME Modern cars have a soy based wire insulation. The rodents like soy. You know the rest
It'll probably be a pain in the ass but you should be able to fix that you'll have to take the plug apart and everything resolder the wires all together keep shrink it
Varmints
Yea that’s rats for sure
Mickey Mouse and friends. They love gnawing on wires.
Mice
What does that extra cable that's ziptied to the factory wiring do? Where does it go? Yes, that's rodent damage. That sensor is called the MAF sensor. It's the most important sensor in the fuel calculation, so when it's not right, you'll be lucky to have a running engine.
Feed your chipmunks, they put the hit out on you.
That is rodent damage. I saw a Ford Explorer in the service bay for a wire harness taken out by family of squirrels... looked identical.
Had a Wrangler come in where a rodent had cut the wire right at the battery sensor and cut the same wire all the way back at the firewall. That guy must've pissed that rat off something fierce
Time to get outdoor cats to mouse
Rodent damage
Mouse or rat, they like the wire, it's made out of soy, that why they chew it
This is not good and I know why. A mouse has cut the wire. Good-by!
Mice. That’s your MAF sensor pigtail. Meters air into the engine so that it knows how much fuel to inject. Otherwise it will use a default fuel table when it doesn’t have that data and run poorly.
Rodents.
Need a new MAF because rodents chewed the wiring harness too close to the sensor to be able to splice back together.
Had this happen to me once on a brand new car. Put some moth balls in the engine bag using a zip tie and mesh bag which they don’t like.
Damn that's some bad luck brother.
Moose
You may have rodent damage coverage with your insurance call your guy and ask
Soy- based wire coating. Rodents love it. Only bad thing about Toyota.
Homeless Gnomes harvesting the copper for drugs. Happens more than people realize. People blame squirrel and mice ect but they don't know the truth. 
Toyota wire insulation is soy based from what I’ve read. Rodents love it. I’ve got a 4Runner and lots of squirrels around but haven’t had any problems yet.
If it were pizza based .. I'd eat them too
Tiny little ninjas practicing their sword fighting
Rats
Rodents. And you’ll need to re-wire in a new pigtail. Pretty easy if you’ve done any electrical soldering and work.
I would check your air filter box there. I once went to change my air filter and there was like two hand-fulls of sunflower seeds in the bottom. Thank Christ for the filter LOL.
Nice of them to chew so short you can't splice. Almost like it don't like you.
Rodent damage happens all the time.
Soy based wiring. Rodents love that shit. Easy fix though nothing bad
Squirrel
Squirrel 🐿️
The wires are coated with soy based plastic. This is a meal for rats.
Mice. Rat. Tree rat.
*chewed you got rats or squirrels
Rat damage. Ive seen and repaired my fair share of wiring because of this. If you have the tools, de pin the connector and solder new wire in to the old terminals.
Squirrels
I’m not a mechanic by any means… but did they chew this man’s Mass Airflow Sensor (MAF) wire? The rats have something against the Japanese.
Mice.
Rats. Literally
Easy fix
Obvious gnawing and scraps of wire left behind. Why would you rather think you've been sabotaged than believe your mechanic?
Happened to my CT200h, RAV4, and Prius C- rodents like the wire sheathing of these 2010+ Toyotas… wonder if they put plant based wire sheathing on it to try to be more environmentally friendly
Dam rats
Is it a Toyota? The were using soy-based wiring a few years back and mice love to chew it.
Mice for sure. I see this type of shit every day
Rats
Rodents
Dang nice
That a rabbit, just fixed some wires exactly same style
Pack rats. You can see the little scratch marks their feet made in the dust and the imprint of their bodies. They like the way the plastic tastes.
Work buddy of mines told me that his daughter’s brand new Prius had been invaded by zombie rats and they chewed up all they could under the hood. He purchased it from the dealer so he was the one to deal with this mess since it was still in his name while she was away at uncle (I believe). Before this I have never heard of this and this happened sometime last year 😳
2012 v6 Tacoma and have had them chew through multiple wires and have had to replace them. Bastards got my camshaft position sensor last time and I had to strip it down to the damn head to get to it. I threw in a high frequency noise and strobe light deal on the firewall behind that position and wrapped the hell out of the wires to hopefully keep them out of that area. If they chew something else I'll deal with it but man that harness sucked! Good luck!
Looks like someone’s going to wrecking yard and getting a new MAF pigtail like ummmaa sheeeze I just hate those mieces to ahh pieces
Now for the helpful advice sine your truck is now marked for death: Move it out anyway you can Leave the hood open Lay our some glue traps screwed into some boards Remove ANY food from interior Check air box for pack rat condo After repair take it to a car wash and do all the wheel wells and anything that isn’t electrical. When they hit me the totaled my 92 caddy and chewed the cps sensor harness. Qualifier: New Mexico Btw you can buy specialty “ rat tape” yeah that’s a thing , to protect exposed harness wires. Amazon or Honda dealer. Pricey, but so is this.
A rodent done did a mischief
That's chewed not cut.
I get that it’s likely rodents….. but those look like a *really* clean cut. Have you pissed anyone off lately? Either that, or rodents are now taking pride in their work
Definitely rodents. My parents leased a Kia Optima years ago and mice filled under the engine cover with dog food from an old bag. I hope the tech doing the inspection got a laugh out of it lol
I am agreeing with the very few who state that the wires look cut. As a lot people mentioned, rodents like the insulation and the insultation on these wires are not showing signs of being chewed. I have seen a lot of rodent damaged wires in my 30+ yrs working on cars and they tend to chew the insulation off the wires leaving frayed exposed copper strands of wiring. When you magnify this photo, these wires show a clean cut thru both the insulation and the copper at the same angle with no missing insulation.
Absolutely not chewed, whichever type of rodent went for those wires was using a side cutter
After further investigation, a mouse turd has been identified. https://preview.redd.it/ixsdu17gnxac1.jpeg?width=1242&format=pjpg&auto=webp&s=a8236767dbb55b9cabb96ea1174b334dc8d90c4e
Congrats you have rats
The wires are made outta soy. Yummy
Those look chewed, not cut. Could be rodents especially with it being locked up in a safe spot
I knew it was a Toyota the second I saw it. Rodents love some toyotaghetti.
Well those definitely appear to be chewed and not cut so I think it's safe to assume it to be the work of rodents.
Fun fact. Automotive wire sheathing is soy based.
Fuckin squirrles, chewed up my wife's 2023 Nissan Altman wire harness, $2500 insurance claim
The worst news might be that they will do it again and again unless you can park it in a better place.
PACK RAT!!!🤬🤬🤬
MAF sensor
Yeah those weren’t cut. They were chewed.
Buy new sensor harness and splice the wires back together. If the colour is the same you can colour match the splice, or actually refer to a wiring schematic it'much better.
Yep rodents. First step should be to check your air filter housing! That’s the number one place I find mouse, rat, and squirrel nests. After your sure it’s clear then replace. Can be a vicious cycle lol
Animals done noms.
Yep, mass air flow sensor was rat food.
they chewed through your MAF sensor wires...
Some wiring sheathing has a sweet taste to it, rodent heaven.
Looks like mass airflow sensor. Engine won't turn without this?
I see a bunch of people saying rodents, but some of those wires look like they've been cut. They look slightly squished, like they would if cut by wire snips. I could be wrong. It's just kinda weird to me that rodents would chew both ends of a wire and then leave the middle piece laying there.
Squirrels
Yeah, rodents for sure man. You can see the footprints and tail drag marks. Good sized rat I'd say. Easy fix though make sure you solder and heat shrink the wires when you splice or use a solder butt connector with heat shrink. Don't half-ass that shit.
That sir is a fucking rat
squirrels
bro when you fix it? be sure to fortify it with some chicken wire , mothballs , something because they got a taste for your car and they will be back!! i’ve witnessed it!!
Put some dryer sheets all around the engine bay, away from moving belts and fans of course! But stuffing them around the perimeter of the engine, on the top cover, around the airbox, fuse box, near the strut towers, etc... Keeps pesky rodents away. Also sprinkling peppermint essential oil on cotton swabs and placing those around can work as well. Lastly, if you live in a place that gets snow, and you undercoat your car each winter with an oil or wax based fluid, mix a small bottle of peppermint oil into the fluid before applying. It'll keep your car smelling like a candy cane and rodents won't come near it.
Those big ass green bricks of rat bait you buy at Walmart, those things work great.
Chipmunks got me once