Audi A3, RS3 and S3 Forum
Prelude: I own Audi A3 8v Quattro
My question is: are parts from, for example, apr, compatible for other tuning companies stage 1 or stage 2 tunes? I bring this up because I am wanting to go stage 2 with IE however, I also want my car to backfire without damage to the catalytic converter. Would...