As the title states my stock muffler is rattling. I really only hear it when the AC is on or if it engine is under a small load like reversing and whatnot. I've checked the heat shields, all the brackets on my DP (which I should state is when I really noticed this issue) but everything seems fine. I did however find out you can replicate the sound even with the engine off if you lightly kick at the exhaust tip. It literally sounds like someone threw a bunch of rocks in the muffler. Has anyone had this issue or knows of a way to fix it?