Remove the heat shield, but first, remove the muffler and can it at the scrap yardMy 2012 JK just started the rattle a day ago. Both my right side bolt holes of the muffler heat shield had corroded through, neither of my left side. It was somewhat easy to access the bolt furthest towards the front of the jeep with a deep socket and a long socket extender. I unscrewed and screwed back on with a big fender washer underneath, leaving the other right side mount unattached. The heat shield is pretty rigid. It seems to have done the trick for now, until other bolt holes corrode. Good (and bad) to know this is a common problem and it is not a larger exhaust repair. If this starts causing rattles again I may go the removal route, but kind of need the other 2 bolt locations to corrode through first.