My 1994 Jeep Grand Cherokee has a broken muffler connection between the catalytic converter and muffler. As far as I know the Cat is OK, but the pipe is broken at the outlet pipe on the cat where it connects to the muffler inlet. I plan on replacing the muffler and tailpipe, but is it acceptable to add a coupling where the Cat pipe is broken, or should I replace the Cat as well?

As a short-term fix, is it acceptable to use a muffler repair patch on the severed pipe? It looks like it's rusted through about 1/3 the way around the pipe.

Thanks in advance for your help!

If your piping is just rusted off whereby the connection is severed to your muffler a muffler shop can probably fix it real cheap. If you're going to replace the muffler and tail pipe anyway then just have it done then. Even if the piping after the cat but before the bolt flange is severed it can be cut off and a new flange can be welded on.