Hey guys I just installed a Invidia q300 and I have a aftermarket cat but I'm getting in-cabin vibration directly off the pipe(it doesn't rattle fitment is tight).

Anyways the fitment was just about perfect but the cat and mid pipe needed a bit of fiddling to get right. It now sits flush against the heatsheild and there is like a little circular piece in that heatsheild as if it's designed to stop the exhaust bumping into it. Anyways it's vibrating(not rattling) heavily because of it.

Any tips on trying to fix it or is that just part of the experience and I should live with it Thanks

 

did you check the exhaust hangars?