Originally posted by Big Chaze
I had the same problem. I changed the manifold gasket, and I still had the rattle.
I'll bet my life the noise is coming form your down pipe.
Get under your car (when it's cool) and give the down pipe a couple of stiff bangs with the palm of your hands. You should hear a knock with each bang. If you do, the inner lining is broken and you'll have to replace the pipe.
Oh, and it cant be welded either.
I'm hearing a loud growl during accelleration, not a rattle. Do you know the purpose of the inner lining?
Is the "down pipe" the pipe that heads down from the exhaust manifold then turns 90 degrees to the cat?