Since I was already under the coop working on replacing the O2 sensors, I decided to try to work on some exhaust rattles. I found and reattached several places with the heat shield fasteners had tore through the heat shield or the nut/washer had rusted off. This definitely needed to be done. Unfortunately I still have a rattle as you step on the gas.. This one seems to be coming from inside the muffler resonator (My Coop has the one ball mod). I checked everything around it and there doesn't seem to be anything close to the muffler and pipe to cause a rattle. Could this be coming from inside the muffler itself? The mufller body seem to be in great shape with no obvious rust damage.
If it is the muffler, how difficult is it to repalce the muffler?

Take Care
Ian