Originally Posted by
Truckracer
Are your current threads stripped or just full of gunk? If stripped you will have to repair the threads with something like a Helicoil or other thread repair insert. If just full of gunk like LocTite residue, you can chase the threads with a proper size tap.
They are just full of gunk. I will try cleaning with a tap but don't know if that will clean enough for thread locker on the new muffler.