Exhaust Problem?

[lambfries]

91 wrangler -
my exhaust is spitting black soot when I start it.
Inside of the pipe is layered with it, and it sometimes drives like something is clogged - almost like it needs a good backfire or or something to free it. thoughts of what it could be from?

[gtmud]

Check your CAT. There is a good chance that it broke apart and is blocking your exhaust flow. Random Tech makes a stainless high-flow cat for about 130.00.