Assuming we all know what it sounds like when a heat shield rattles(like the common one that rattles on the cat).. im getting that sound but, none of the heat shields are loose. ive even had someone rev the motor while i hold the heatshields in place. Im still hearing the noise. I was wondering if the baffles in the resonator could have broke. its a greddy evo 2 catback system but its only been used for maybe 6 months? Any other ideas. and its only really noticeable when driving... any ideas?

 

dont know what to tell you.. does it do it right at around 3500 rpms? if so its the heat shield under your car ha. it shouldnt be the hard to locate a rattle noise on your car.

 

Yes the baffles can break off inside and also chamber walls inside of the muffler can break off. I am having this problem with a World Sport right now. If you already checked the heat shields you can its probably in the muffler or resonator.
I have something broken off in my muffler and it rattles loud when ever you let off the gas after revving for a shift. I am cutting it off and welding on a new one in a few days.
The exhaust might also be loose and vibrating on the undercarriage somewhere.

 

ill check some more today but, the wierd thing is that, i revved it with the exhaust on and it did it. then i unhooked it right after the resonator and it didnt do it. If i take the heat shields completely off, will that hurt anything in the long run?

 

Probably not, I know people who have taken their heat shields off. I can't say that I'd recommend it.
I think there are some spray on undercoatings that act as a heat shielding also.

Sounds like there might be something broken in your muffler, either that or its vibrating off the undercarriage. I you put it back on and hold it away from the car and have someone rev the motor you should be able to hear exactly where the sound is coming from.