My 98 gsr had a high flow cat put on the other day by a muffler shop. Also have greddy evo2 cat back exhaust. Anyways, i was wondering if anyone else expected a different sound to come from it. It almost sounds as if it is rattling. I can hear it right under me when driving. I expected my exhaust to be louder which it is, but the rattling noise im not too fond of.