i have megan 4-2-1 headers, catback exhaust, comptech intake pipe and a KN filter should i get a high flow cat, the rest of the exhaust from the headers to the cat or intake manifold, vafc, cams, pulleys, "fuel rail"(yeh ok), i really have heard intake manifolds barely do anything but i was wondering what i can do with about 500$?

THX word to the lude's