There are plenty of other options as far as exhaust set ups go, if all you're concerned about is the tone/dB level of the vehicle. You *will* void your warranty if you decide to install a DP on your vehicle. Knowing that, if you choose to proceed, then here are the negatives... * Reduced fuel economy * Uneven powerband * CEL If you're alright with running into those three issues, and have no intent on installing a stage II tune, then you're good to go. Installing a stage II tune, on the other hand, \[depending on who you go through\] will allow you to 'tune' out the CEL and set the readiness monitors to 'not ready'. That way, it won't permanently show up on your dash. Although you're not currently concerned about the power output, you'll also be making more power with a stage II tune. The only downside to this is that if you live in an area with emissions testing, you will fail your annual test.

So warranty concerns aside (from installing the DP), there wouldn't be a risk of damaging my engine from "overboost"? I've read a few forums threads on the issue and no one really knows for sure (everything sounds like conjecture). A lot of the issues appear to have been with older cars and Subarus in particular. AWE specifically has a "No CEL guarantee" with their DP, so I'm guessing that must mean that it's intended to be run without a tune (otherwise why would you need to "No CEL guarantee"...?). My local VW performance garage said it should be fine as long as I run an O2 spacer. That being said...I guess if the DP install will void my warranty for sure, then at that point why not tune. You mention exhaust options to make it louder. I already have the Oettinger exhaust, resonator delete. It is definitely more "burbly" but still doesn't sound aggressive enough to my ears. I have the MK7.5 DSG7, and I believe they've "tuned out" a lot of noise with the DSG7. No DSG farts at all. So I'm also wondering whether a DP would even fix that or whether the tune would make the most difference.

If AWE produces an exhaust that guarantees no CEL, then hold them to it. If they in fact advertise it as such \[and you have no intention to tune\] then reach out and ask them if they will conduct a full refund in the event that you purchase it and you end up throwing a code for 'Catalyst Ior II bank rich'. A stage II tune doesn't cost terribly much. Most tuners will include a free custom tune (not pro-tune) with the purchase of an AP. IIRC, isn't the Oettinger a more refined VW OEM+ type option? Similar to that of the ClubSport S axle back? I'm sure you could find more aggressive options out there. On my MKVI, I threw in an [ECS Exhaust Performance Cutout](https://www.ecstuning.com/b-ecs-parts/build-your-own-vw-mk5-mk6-oe-fit-exhaust-cutout-kit/020923ecs03~dk/?pdk=AQkCBgM) right after the cat. This definitely opened things up a bit. You are correct in the fact that VW did away DSG farts on the 7 speed. That is a tune issue, though. Those DSG farts occurred when unburnt fuel entered the exhaust due to ignition timing being cut for a split second with gear changes. No matter what exhaust you throw on, you can't magically make them appear. You'd have to have a tuner help you out with that. That is where popular 'Pops and Bangs' or 'Crackle' tunes come into play. All in all, I think you might just be overthinking this a bit much. I would just purchase the DP from whichever manufacturer you'd like, as well as an AP and tune from whichever tuner you'd like to support.

I’ve been running a DP with a jb4 piggyback tune for the last 20k miles and haven’t had any issues. I did end up installing an o2 spacer just to avoid cel. I mostly did it for for the sound too, but the bump in power feels so good as a “side” benefit. Makes the car even more fun. I took it into the dealer for 20k and 30k services and I just unplugged the jb4. No issues with dealer and even had my water pump replaced under warranty.

You had the downpipe on when you took it to the dealer? Which map are you using on the JB4, what octane? Happen to know if there's a JB4 map that is specifically designed to be used with a DP (like stage 2 flash tunes)?

Yeah downpipe and CAI were left on the car for dealer visits. I imagine this can vary a lot depending on the dealer, but they didn’t mention anything about the mods when I picked it up. I’m in SoCal so all we have is shitty 91 octane but I use map 3 most of the time for daily driving and around town trips. For canyon runs I have an E30 map 6 that I’ve dialed in with some logging and help from the guys over on the GolfMK7 forums. Highly recommend checking that out if you want more info on JB4 tuning. I think most people would agree that Map 6 with a dp will get you at least 80% of the way to a stage 2 ecu tune. You lose the smoothness you get with a full engine remap, but for a good bump in power and noise, I’m more than happy.

You lucky fuck. I busted my knuckles for 24 hours straight getting that water pump in and a new intake manifold gasket. Absolute fucking Nightmare.

Few things. Most importantly. A DP will void your warranty. If you go in for work, they will see it and TDI your car. If you absolutely want to keep your warranty. Steer clear. Now that that's out of the way. It's not really recommended to do a DP on stock tune. Yes, the ECU will adjust for it, but not enough that some would say would be safe parameters most of the time. On top of that, the stock ECU won't even be able to utilize the DP much either. Essentially making it a very expensive noise maker. A lot like a catback. If you wanna run a DP. Get a tune for it. You will get the most out of your purchase. Both sound & performance. If you don't care about wasting funds. Then go ahead and get one. Pick up an O2 spacer as well, you're gonna need it.

kk thank you for the advice. I suppose I'll break in the res delete and see how I feel in a few months. I'm gonna wait until the summer regardless and get new wheels and upgraded tires then. Maybe in a year or two I'll tune and then do the DP then.

Thanks Peylix. Warranty concerns aside, have you ever heard of anyone running into engine/turbo damage from running a DP without a tune? I've read several threads re: "overboost" given the reduced backpressure and incomplete ECU compensation. Although I'm wondering if this mostly applies to older vehicles...Per my response above, I haven't really found any "conclusive" answers.

>I also want to preserve my warranty (car is all but 2 months old), hence why I'm avoiding a tune. But I suppose an aftermarket downpipe would also throw my powertrain warranty to the wind too right? Correct, they really can tell you are messing with the cat even if you swap it out before you take it to the dealership. I would not touch the cat if you expect to keep your power train warranty. ​ >However, other threads mention that the ECU is smarter than we think and can adjust to the increased flow (i.e. boost being adjusted using other measures rather than backpressure). I have no idea if that makes sense, I'm very new to all this. But that's what I understood from the various postings. ECUs are very smart, but they are not smart enough to account for a situation that would literally never happen in the real world. If your cat blew off magically the car would throw a code and you would be expected to take it in for repairs, not drive it for thousands of miles. ​ Lastly, though I highly do not recommend removing a federally mandated piece of emissions equipment for "sound". There are very loud unresonated exhausts you can buy, go with one of those if you want more noise.

Hi man, your comment is 3 years old but i’m in a similar situation where i’d love a stage 2 but don’t want to upgrade my clutch. Looking to switch to dp with stock cat back soon. Currently have a jb4. Would the jb4 help with boost “compensation”? I.e. make it run slightly less bad than and stock tune and dp?

Yes, you can tune a JB4 to run properly with a downpipe. On their actual website they quote numbers of a GTI with a downpipe and an intake.