My tailpipe is rattling against the plastic trim where it emerges. It only rattles when I push on the gas going uphill.

The tailpipe and the rear muffler are the only part of the exhaust system still original. I should mention that as far as I can recall the tailpipe has never been truly center in its hole in the plastic trim. It has always been very close but not touching one side of the hole. Oddly it's only now it's been rattling.

I've tried without success
1. replacing the exhaust rubber mounts which were deformed
2. loosening the axle pipe clamps and pushing/kicking it but it will always come back to its original off center position
3. loosening a bit the metal bracket holding the rear and middle muffler

Any advise on how I can center the tailpipe in its hole?

Thanks

Aslan