I have a stock 2002 Z28 exhaust, with a rattle at the clamp where the Y-pipe connects to the single pipe going to the muffler. For some reason I can't get that clamp to tighten such that the rattle is eliminated. It'll tighten, but doesn't seem to affect the joint. It's not a typical clamp either, do I need a new one? Is there something particular about this joint?