# APR downpipe on S3 without a tune....



## crackkills (Mar 10, 2007)

Will it throw a check engine light? I would get one with the cat. I assume it will and I will have to run a spacer. Not doing a tune for a while cause I loves me some warranty!


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## BBaskett (Apr 13, 2010)

If it's thrown a CEL without a tune on pretty much every other VAG vehicle, then I would assume it's safe to say it will do the same for an S3.

The cat in the APR down pipe is way less restrictive than the stock meaning the chances of throwing a CEL is higher but you necessarily don't need a spacer. If you want to increase your chances of avoiding and CEL, I would include a spacer then. 


Sent from The Armpit of America


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## BBaskett (Apr 13, 2010)

It's only beneficial that you have a tune for the correct mechanical setup, but not _required_. The less restrictions turbo engines have, the better they perform throughout the rev range. The last worry you should have is "grenading" your engine from an aftermarket downpipe. 

I don't know what's with those Subaru guys getting a tune for every little thing.


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## turbo slc 2.9l (Dec 4, 2003)

Doesn't adding an aftermarket downpipe also void the warranty? Unless you take it off each time for service I guess.. 

Can anybody else elaborate on this? I was under the impression that while under warranty, messing with the exhaust (even removing suitcase mufflers) is frowned upon by the service dept..


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## lilmira (Feb 4, 2014)

Technically speaking, an aftermarket downpipe fits the description of powertrain tuning. They even use cold air intake as an example. Would the tech enter it into the system? YMMV.


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## crackkills (Mar 10, 2007)

It doesn't cross your mind that these "tuners" are just trying to sell you products saying that the tune is required with a downpipe? They are trying to sell their stuff. My logic, humor me and go with this, is that the cat being further away is going to help with heat buildup and less heat means more longevity. I am not expecting any HP gain. If I get some great but I think the area that is most restrictive is the downpipe and not the cat back portion of the exhaust. You are really just gaining sound with an aftermarket on this car that has dual outlet for a four cylinder. 

I am also going to ceramic coat the downpipe prior to installing to help with heat even more. I am also going to put more heat repellent material between the top of the turbo and the hoses and lines that are above the turbo. I am also going to put more heat reflective material around the housing of the ABS pump as that is pretty close to the downpipe. I know the downpipe has a heat shield but I want more. I am also considering thermal wrapping the downpipe after ceramic coating. Lastly, I am going to wrap the hot side of the turbo with a blanket or at least the top side of it. 

I will also wait to see the intercooler development for this car and change that as well. All of this to maximize the efficiency of the stock set up. The tune is going to be much later down the road as I want to see some serious mileage on this car with members to see what weak links, if any, rear their heads on this platform.

The TT RS has been a very bullet proof engine and turbo but it did have teething issue with tunes from some of the tuners that included misfires and limp modes. Those issues were first denied by the tuners and then they finally fessed up and changed the tune. I am going to be patient as to modifying this car.

With that said, I would think APR that constantly posts on here to at least answer a simple question as to check engine light with aftermarket downpipe that has a cat.


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## BBaskett (Apr 13, 2010)

Instead of posting on here and hoping for a response, you could just email them. Better yet, give them a call.


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## crackkills (Mar 10, 2007)

BBaskett said:


> Instead of posting on here and hoping for a response, you could just email them. Better yet, give them a call.


I did. The person on the phone said I would have to contact a dealer as they don't know if it would cause a check engine light!!


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## davera3 (Jul 26, 2014)

Perhaps I'm missing something, but at the moment, I don't believe APR has their downpipe for the S3. Its only for the FWD A3 1.8/2.0T, not the AWD A3/S3. 
Am I missing something?


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## [email protected] (Oct 11, 2013)

There is no APR downpipe out for the S3

These are the only ones that we have right now from the top brands 

http://www.moddedeuros.com/audi/s3/8v-2015/exhaust/downpipes

You can run a downpipe without a tune fine. It just will throw a CEL. You can get a spacer to combat it. That is what will cause the dealer issue (the CEL). We are installing the CTS turbo one on our car in the next week. 


CTS Turbo 3.5" Downpipe (15+ Golf R, S3, A3 Quattro)


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## crackkills (Mar 10, 2007)

Thanks for clarifying. I like the manufacturing process of the cast downpipe. What is the warranty on this product and I assume it will fit the stock cat back? Thanks again.


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## [email protected] (Oct 11, 2013)

crackkills said:


> Thanks for clarifying. I like the manufacturing process of the cast downpipe. What is the warranty on this product and I assume it will fit the stock cat back? Thanks again.


Warranty on CTS or APR? For CTS there is a 1 year manufacturer warranty against any defects. We actually put product warranty info on every product that has one on our website under a warranty tab so if you are browsing other products feel free to check them out


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## Syrome (Jun 12, 2015)

I have a HG Motorsports BullX catted downpipe with HJS 200 cell cat in both my S3 and A3 2.0T. It did not throw a CEL without a spacer before I got the Stage 2 tune on it. While more expensive than the other options here, I am wholly satisfied with the quality, performance and sound.

As for the crackles and pops someone mentioned, pretty sure that's very difficult to do with just exhaust modifications or cutting something out. It has more to do with engine timings and such. AMG spent thousands of hours developing that crackle and pop for the CLA45. So hard to get out of a 4 cylinder, but they did it. It sounds good too. 

For warranties, you can obviously swap out bolt ons should something break...so if you are concerned about anything, perhaps just doing a DP with a piggyback might be a good option. People are running the Jb1 with good results. 

Sent from my iPhone using Tapatalk


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## crackkills (Mar 10, 2007)

Did you do the install yourself? Did you go with a non resonated matted to the stock exhaust? That is the route I want to go and hope to get a little bit more sound but nothing crazy as I don't think four bangers sound all that great anyways.


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## Syrome (Jun 12, 2015)

I had my Performance guy, who is also the importer for BullX, do the install. It replaces both cats and res in the stock down and mid pipes and replaces with a 3" pipe with HJS high flow cat. I have the stock valved catback on the S3 and the noise is definitely more noticeable. I set off car alarms in the parking garage, if that puts it into perspective.  but it's totally controllable since the valves are all stock. 

I also never got a CEL for O2 sensor and didn't have a spacer either. I also know of one other guy who did the same thing and didn't get a light. 

Sent from my iPhone using Tapatalk


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## Flying Tomatoes (Nov 29, 2012)

If you get a catted down pipe it shouldn't throw and error code


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## AwdOwns (Mar 29, 2009)

[email protected] said:


> There is no APR downpipe out for the S3
> 
> These are the only ones that we have right now from the top brands
> 
> ...



Hey Sean,

Does the Billy Boat downpipe also taper down from 3.5inch to 3inch like the CTS and Bull-X? If so i'll be placing an order shortly.


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## 1998GTIVR6 (Nov 28, 2005)

The idea of the 3.5" elbow coming out of the turbo is good and flows well but the transition from 3.5"to 3" after the elbow is not good at all. From looking at the pictures the pipe does not taper smoothly, the angle (the part where it funnels) is too sharp and the flow is hindered. I prefer something like a 3" with not abrupt funnels. The end of the pipe where it meets the cat-back looks well.


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