heres my scenario.... i have a built y8 with cai, header, greddy evo(first one) and a 2.5 in test pipe. now, my car is really loud now and i cant understand why. granted when i put the test pipe on it became louder than it was b4 but what really boggles my mind is that one of my boys has an ej8 with a jdm h22 with the same exact bolt ons(apex n1 instead of greddy) and his car is much quieter than mine. Now, I thought that n1's in general were much louder than greddys even in stock applications, what i was pondering is that since the greddys basically rot away over time and my resonator is rusty on the outside, is it possible for it to rot away on the inside??? to try and remedy this im gonna put a high flow cat in place of the test pipe and maybe get an additional resonator bcuz its loud to the point where my friends can hear me buzzin around town no matter where i am. Especially now that its gettin colder out, its only becoming louder....thanx for any input!!