Exhaust Issue

[SolarBunny]

So my car started to sound like it had a small exhaust leak and then quite quickly it got really loud and I took it in this morning. I have been told that I have to replace the entire pipe and they cant just replace the pipe that the cat is attached to it. I havent been under my car and Im wondering if this is actually true. I have never heard of this being the case before... any help would be appreciated ASAP thanks!

[Akfahad]

depends on how badly the rest of the piping is. if its pretty rusted throughout, i'd probably go ahead and replace it, if not and money is tight, they should be able to just grind the opening down a bit and weld a patch piece over the hole.