I have this horrible sound coming from my exhaust actually the sound comes right after the cat connects to the exhaust pipe.It only happens at low rpms or right after I let off the gas.I took off the heat plates that covered the cat and also the flimsy metal where the o2 went through.Ive searched everywhere and everyone said thats more than likely the problem(the heat plates).Anyone else have this problem with an after-cat exhaust .Ive heard about exhaust clamps.Do they work has anyone tried them.Any help is appreciated.By the way its a 2.5 Hayame after cat on a 97 ex(damn should have gotten a Greddy)