Taking mine in this morning (just got it last Thursday) for the same thing. (2nd time its been in there for this) in the last 5 days. I am SO glad I have found this web site. I am going to have my hubby put a new exhaust on it anyays. I think it's sounds kinda girlie for an SS. This coming from a girl
I put GM GFX on it and I thought maybe it was doing it because of that? There is also a bump, possibly a bolt that you can feel that sticks out on the rear passenger corner bumper. I think they scabbed on my GFX too fast because I wanted my car NOW!