[izzydjinn]

Welcome Mike. Ok, let's solve your problem. I think is your exhaust......... and to be exact, it a metal plate that kinda holds/guides the exhaust just as it curves to the passenger side. Probably you run over a bump to fast or ran over a rock that caused that plate to bend upward thus causing the exhaust to hit it as it shakes or rattles. Because it does have to have some free play, the exhaust.