I installed my wsp y pipe and high performance cat converter today. It was cool until I started down the road and got this buzzing noize when Im in 1,2,3,4 and 5th 50 mph and above im fine. Hell even when i rev the car im ok. It sounds like a ice box

 

itll go away in a few days, its an inherent trait when the pipe is being broke in, if not its those two brackets attached to the cat conv, bend them away from the body with a flathead screwdriver, i had the same problem, it subsided within a few days, just drive like 200 miles and itll be gone

 

u think so? I stuck a hammer next to the flex and it stopped the rattle. Thought about taping it there...

 

if you said you stopped the flex from shaking, then its probalby still being broken in, i had it for like 200 miles, i had another rattle, but that was due to me not clamping the exhaust to the body, but Dallas from WS told me itll go away, he knew right away wehn i said rattle, and surely enoguh he was correct

 

could be your heat shield...many people report that. there's a tsb on rattling exhaust i believe, check that out, can point to problem areas, or check your heat shield. mine fell off so i don't have that problem.

 

yeah, good point, but why would it be rattling after the ypipe? is the heat shield the one on the cat conv? or the aluminum shield attached to the chasis? i recall bending soemthing with pliers so it wouldnt touch, but im not sure if that was the cause, i remember a buzzing noise, i dont konw if thats the noise your talkinga bout, the other noise was a clunking noise that got faster between clunks when the exhaust clamps for the cat convertor were not on, after i put them back on, it was fine

 

I have no heatshielf! the high performace cat converter i got from dallas has one welded onto it.. and the stock one wont fit, there was originally something welded onto the stock cat to attach it to the cat converter. So my mechanic took a look @ it and said it wasnt necessary.