Sorry if this was already covered, i tried to search but i found nothing. I just had a shop put a 3 inch exhaust on my s/c lude. It has a vibrant flat black muffler and vibrant 18 inch resonator, but it doesn't have a cat. i just picked it up a few hours ago and it sounds really good until you hit like 3,500 rpms then sounds very raspy. Now my question is would I be better off using a high flow cat or putting another vibrant resonator on?