Does anyone have high flow cats in their B6 3.0? I just turned over 80k miles in my 2003 quattro six speed and have developed a rattle in my right cat. Emissions warranty goes to 75k if I remember correctly.

I have a custom cat back exhaust and intake and am thinking adding high flow cats will free up some more power. A cat from audi is over a grand so I was thinking of getting two high flow universals and fitting them in.

My only concern is about the oxygen sensors and tripping a check engine light. I have had the car up on the lift a couple times to try to locate the o2 sensors but have not had any luck.

 

anyone??