Exhaust Removal - Hot or Cold?

[vesnyder]

I gutted an old muffler and want to remove my current muffler and try the gutted one, but was wondering if I should heat up the engine, or leave it cold - which way will make it easier to remove the muffler from the car?

[goat]

Cold.
I had to dremel the bolts off cause they were quite rusty.
Added a little time to the project.

[efhughes3]

I wouldn't mess around with the PB blaster. Go straight to the torch-less cursing and you'll get each nut off in fairly short time. You need to use something stronger than a propane torch, and get them red hot. A quick blip toward tight, and then the nuts should back right off.