I upgraded my exhaust's muffler to the Gibson Metal Mulisha and the muffler is a lot further back than the stock one. I've been hearing a rattle at exactly 1300 rpm and it comes from right below the trunk. Could it be from the muffler hitting the frame? It so, can I put like a piece of styrofoam in between them or would that melt?

 

do you still have the heat shield up there? On mine the heat shield bottles things came lose and it sat on the muffler. Maybe one side came off and is rattling

 

I've checked the heat shield a couple times and it seems to be fine

 

Styrofoam will definitely melt, and it would probably make a mess and stink. The muffler does look really close, and if the noise didn't start until after you did the exhaust, then that's probably the source of the noise. The only thing I can think of is to work on the routing of your exhaust. Take it to a muffler shop and have them work on it to move it away from the frame, unless it's something you can handle yourself. Anything you try to wrap around the muffler or put between the muffler and frame as noise is probably still going to make noise, if it doesn't melt first.

 

Are you sure the tubing is seated all the way back within the other pipes. Could give you an inch or so.

 

I was going to try that tomorrow. I'll report back after I attempt it. If not, could I just take a hack saw and cut a couple inches off the piping?

 

Axle back or cat back system?

 

Cat back

 

Is the positioning nipple on the factory pipe from the cat messing with it?

 

I'm sorry. I don't follow