You need to check with the jeep gurus on this one, but here are my thoughts...
1. All the big muffler manufacturers claim that a hi-po cat will flow really darn great. If you're using stock manifolds, using a hi-po cat would probably not cause you a whole bunch of restriction...
2. Cats need lot of heat to work right...there are probably some sensors that will go banzo-kazooie if you just pull the cat...
3. Too little backpressure (again, this is probably not a concern with a stock manifold...more of a concern with too big of an exhaust and headers) loses that exhaust vacuum scavenger effect and actually hurts power production...
On the other hand:
1. I don't run any cats on my engine and it runs great...but it is a 77, and the cats were more of an after-thought on it. Try to get one of our engine guys on this.
I know that this isn't the definite answer that you are looking for, but as us youngsters begin to learn, we like to theorize about these things and then let the more knowledgeable folk show us the error of our ways.
Measure once, cut twice...or is that the other way around?
