After I went ahead and decided to get my car tuned on a dyno - i decided to take off the cat when my mechanic told me about the APR Test Pipe ECU flash which regardless of whether or not I have a cat on there, no engine codes come up - in effort to get my turbo to spool a little quicker I took the cat off and replaced it with ordinary stainless steel piping. If anyone is in the market for a catalytic converter for a B6 A4, it was removed when the car had 62,xxx miles on it and is in perfect working order. I'll let it go for $200, I'm assuming audi charges an arm and a leg for the part like they do with most things. If anyones interested feel free to PM me on the forum or shoot an email over to cooperscooper@gmail.com

Thanks!

-Coop