Originally Posted by cbags05
Why do they allow aftermarket cat-back exhausts then? And K&N air filters? Do they not improve the car very much at all? I put in a K&N air filter and noticed a slight improvement...slight, but nonetheless.
why? because it's allowed.
if you can actually feel a difference with a K&N I got some bridges I want to sell you.
neither of those do much for you in an autox.