What's up HCF...I am having a few problems with my exhaust..I have a hole in the "s" bend from the resonator to the muffler..I found a stock exhaust from the header back for the replacement part but I wanted to install a obx muffler..I also hear a rumbling noise right under my drivers seat...I'm thinking maybe the cat or the resonator I'm running now..am I right in assuming that??...any help will be appreciated...