I'm currently running a Greddy 2 Evo, with a cattman Y pipe and a straight pipe.

Every time i step on the gas hard, it sounds like there is a knocking sound. My mechanic says its because the bolts odn't match up with everything i got and the engine moves slightly causing the parts to knock....i bought this crap for the last few years, but figured since then:

(a) some1 had to have had this problem and
(b) someone had to have figured out how to solve it.

I hope i'm correct at least partially. Any1 know how to stop it or even know what i'm talking about?