Downpipe and Emissions testing

[coolwater]

Those of you that are running a downpipe, how are you guys dealing with emissions testing?

I had looked at the CEL-free high flow cat/downpipe setups, but most don't have the OEM mounting bracket on the turbo side with Milltek being the only exception.

I've also heard that some downpipes with the magna flow cat at the stock location have been able to avoid a CEL even without a spacer.
However, it seems that most also don't have the OEM mounting bracket except for the unitronic one.

The downpipes with the Cat in the bottom section will most likely flow better since no cat immediately behind the turbo and it should put less weight on the turbo. But this setup will most likely throw a CEL when going to emissions. The ones with the stock location for the Cat don't have OEM support brackets and just hang off the turbo except for unitronic.

Interested to hear experiences from those of you that have installed a downpipe and if you were able to avoid the CEL without software.


-cW

[Nightmare1708]

Don't worry about the OEM mounting brackets. They're only there to support the weight of the stock downpipe which is much heavier than the aftermarket options.

[coolwater]

Don't worry about the OEM mounting brackets. They're only there to support the weight of the stock downpipe which is much heavier than the aftermarket options.

I would like to believe that, but there are some of the CEL-free downpipes that have cats just as big as oem.

-cW

[will13k7]

The AWE one is CEL free guaranteed too, it's the one I'm getting, partly due to the guarantee, and partly due to matching it with my AWE exhaust.

In CA you can still fail the visual inspection if you get a tech who actually is looking for it and can notice an aftermarket one. I'm going to roll the dice on this and swap it out only if I have too.

[coolwater]

The AWE one is CEL free guaranteed too, it's the one I'm getting, partly due to the guarantee, and partly due to matching it with my AWE exhaust.

In CA you can still fail the visual inspection if you get a tech who actually is looking for it and can notice an aftermarket one. I'm going to roll the dice on this and swap it out only if I have too.

I was thinking about the AWE one also since there is 20% off right now and free install at TAG. Wonder how heavy it is compared to stock...

-cW

[JohnnyUtah787]

How, if at all, will a new downpipe impact the vehicle's warranty?

[coolwater]

How, if at all, will a new downpipe impact the vehicle's warranty?

If your check engine light comes on constantly then I would think it's an issue.
If no CEL, then you're good. I'm sure you could tell the service advisor to not plug you into the Audi scanning tool.
But yes, this is a concern for me also since I have audicare and will go in for service.

-cW

[JohnnyUtah787]

If your check engine light comes on constantly then I would think it's an issue.
If no CEL, then you're good. I'm sure you could tell the service advisor to not plug you into the Audi scanning tool.
But yes, this is a concern for me also since I have audicare and will go in for service.

-cW

Would love to go stage 2 myself, but violating my warranty is not something I intend to do. Very likely I will just do stage 1 with Eurodyne and leave it at that.

[EmmanueleDesign]

Without using a spacer, the best option is going to be an HJS Euro 6 catalyst. This unit is approved for European emissions, so it will pass US tailpipe but you still have to consider the visual. I believe AWE offers a Euro 6 option, as does Bull-X:

http://www.emmanueledesign.com/colle...utlet-downpipe

[S3Danny]

No emissions testing here. Have yet to have a CEL with Revo's catless downpipe and stage 2 tune.

If you just need to pass an OBDII test, then you either need an O2 spacer or a tune that turns off the rear sensor. That may also fail as the sensor will not show ready. If you need to pass a visual/sniffer test, you have no option but to put the factory down pipe back on for the test.

[hamz01]

I have the CTS downpipe, catted, with spacer. Not tuned, no CEL.

[coolwater]

I have the CTS downpipe, catted, with spacer. Not tuned, no CEL.

Nice, which spacer you using?

-cW

[coolwater]

Without using a spacer, the best option is going to be an HJS Euro 6 catalyst. This unit is approved for European emissions, so it will pass US tailpipe but you still have to consider the visual. I believe AWE offers a Euro 6 option, as does Bull-X:

http://www.emmanueledesign.com/colle...utlet-downpipe

I won't need to pass tailpipe inspection and I like the bullx pipe, but I would like the stock mounting brackets.

How much does the top section of the downpipe weigh?

-cW

[hamz01]

Nice, which spacer you using?

-cW

The one that comes optionally with the DP from ModdedEuros: https://www.moddedeuros.com/products...ts-exh-dp-0015

[Mr.Jetta]

CW - my catted USP had no light with just a 14mm spark plug fouler from autozone... it was $3 and threaded into the DP. took 2 min under the car to do.

[coolwater]

CW - my catted USP had no light with just a 14mm spark plug fouler from autozone... it was $3 and threaded into the DP. took 2 min under the car to do.

Thanks for the info. Good to see that foulers and spacers are working.

-cW

[coolwater]

The one that comes optionally with the DP from ModdedEuros: https://www.moddedeuros.com/products...ts-exh-dp-0015

Did the cts turbo downpipe require a O2 harness extension cable? Since the cat was moved below.

-cW

Sent from my SM-G900V using Tapatalk

[ModdedEuros]

Did the cts turbo downpipe require a O2 harness extension cable? Since the cat was moved below.

-cW

Sent from my SM-G900V using Tapatalk

No extension needed. I run the CTS one on my S3 right now. These downpipes btw just literally went on sale today part of CTS's end of year sale


https://www.moddedeuros.com/products...ts-exh-dp-0015

[coolwater]

Great that it's on sale, but I see the cat is moved to near the mid muffler. I don't see how the O2 harness can reach there without an extension.

You got some in cabin sound clips with the stock catback?

-cW

Sent from my SM-G900V using Tapatalk

[coolwater]

Ordered the AWE non-resonated downpipe. Called AWE and they reassured me the extra mounting tabs on the OEM cat were not needed for the AWE downpipe. Guaranteed no CEL and took advantage of the 20% sale...

-cW

[will13k7]

Ordered the AWE non-resonated downpipe. Called AWE and they reassured me the extra mounting tabs on the OEM cat were not needed for the AWE downpipe. Guaranteed no CEL and took advantage of the 20% sale...

-cW

sweet! I ordered their resonated one last Thurs, can't wait!

[coolwater]

sweet! I ordered their resonated one last Thurs, can't wait!

Yes, can't wait also. Probrably won't get it till next week. Hopefully they remember to include the reducer to connect up the stock catback.

-cW

Sent from my SM-G900V using Tapatalk

[selp]

No emissions testing here. Have yet to have a CEL with Revo's catless downpipe and stage 2 tune.

If you just need to pass an OBDII test, then you either need an O2 spacer or a tune that turns off the rear sensor. That may also fail as the sensor will not show ready. If you need to pass a visual/sniffer test, you have no option but to put the factory down pipe back on for the test.

Havent heard much on the Revo downpipe.
Care to talk about fitment, sound, and other comments you may have?

Regards