Originally Posted by 94bmw325i
did a hi-flow cat make a difference in sound w/ a stock exhaust? My cat is screwed I think, so I will probably need a new one...
Don't know I had a full stainless catback system fitted too. The whole lot together makes a slight difference to mid and high end performance too - not 30 horses or anything like that but a noticeable difference. Next I want to get a pair of polished stainless manifolds (headers) and down pipes and there should really be a difference then.