ok i got a custom catback exhaust and the guy cheaped out on using my old stock flanges. the piping is 2.5" all the way, would using the old flanges restrict some flow or mess it up because of the smaller flange? and also the exhaust doesn't sound that great at certain rpm's. it sounds like a ricer exhaust...it has no resonator just a straight through cat back
would adding a resonator affect the performance and would it get rid of the annoying ricer sound?