[JTsM3]

Anyone have experience with Active Autowerke Downpipes with GESI CAT? Specifically I'm interested if you have noticed any improvement at stage 1 or are you running stage 2?

Currently I am running Valvetronic full cat back single mid pipe system and I'm happy with it. I have a BM3 stage 1 ACN 91 tune and flex fuel sensor installed. Wondering if you have experience with any benefit of the higher flow catted downpipe and move to stage 2.

I tend to think stage 1 with better gas would give a bigger benefit than stage 2 at ACN 91 but that's what we are stuck with. At least I can run an E blend to partially compensate.

[mike@x-ph.com]

It's probably the most popular downpipe, with many posts about it.

You will get more sound, better airflow, and no check engine light.

downpipes will not affect gas mileage, but your driving habits will.