The rear muffler connection to the axle pipe has broken off. However, the resonator, its connections to the cat pipe and the axle pipe, and the tail pipe connection to the rear muffler are all still ok. By that I mean there are no holes, though there is surface rust around each of these connections.

So I can either:

1. remove the tail pipe and the remainder of the rear muffler sleeve on the axle pipe, and then just replace the rear muffler, or

2. do everything from the cat back

Anyone ever done just a partial fix like this? If so, was it worth it?

Or is it standard to just do from the cat back when part of the system goes? And why?

Thanks