long tube headers
 

I have the ark grip exhaust and the fast intentions long tube headers. When I go full throttle it sound like the headers are vibrating on something or sound like they might fall off. Even tho they dont hit anything and are on tight as hell. Is this normal?

It's probably the exhaust hitting the crossmember

crossmember? i think i took that off when i took off the stock cats...

I believe it might be this crossmember:

http://www.the370z.com/members/semte...0-p1000871.jpg

ahhh ok yea. Probably stick some rubber pad in there.

I would check to make sure all your hangers are in properly, one could have gotten lose.
There are a couple threads on here about the exhaust hitting that. Mine recently did because something to under my car and bent it and the shop bent it back so that could be an option.

its an easy fix. Loosen all the connections on the exhaust, then take a jack and jack up the center section until its an inch off that cross member. Now tighten the exhaust starting at the header end and working backwards. ONce its all tight, remove the jack, and the exhaust will stay 1/2" or so off the crossmember.

It was actually the left O2 sensor hitting the heat shield. I took the heat shield off and all good now. For some reason the left sensor sticks upword more then the left side one. I think during fabrication it was slightly distorted during welding. Still think they could of turned them down another half an inch for sure.

Glad you found out the noise.