it could..
does the jeep feel sluggish?
wait till it cools down a bit and see if you can tap at the cat.. listen for anything loose in side of it.. as the catalyst burns down sometimes it makes a ball or clump that can get in front of the exit..
iirc when my cat was going bad it started burning more fuel...
good luck.. let me know if you want a hand
gut the cat
thanks man i appreciate it, its cooled down now so im going to walk outside and check the whole exhaust system and find where its rattling at..
brb 
just throw a test pipe on in lieu of the cat ;D
yeah well im pretty sure its the muffler now.. I started it up and climbed under and even put my hand to the muffler and just felt it clankin and clankin..
who votes for cutting the muffler off 4 cyl straight pipe roar!! 
i gutted my cat 2 weeks ago and the jeep ran better then ever and better gas milage too
They used to sell test pipes to put on to test the cat. If your gas mileage went up then the cat was bad. The problem was that people would just leave the test pipe on. They do a visual so you have to have it on there. The rattling is probable just the heat shield. Over time the spot welds break and the thin metal rattles.
my cat rattled now my muffler and cat rattles hehe I think the stuff in my cat has moved to the muffler. some day it might come out the tail pipe. I had the xj throwing codes on the way down to spring fling, had something to do with too rich after the cat... so I assume my cat screens have come loose. ehh engine light is off now so I dont have to replace anything yet. I got two more years before inspection. so I am good.
has not affected my millage but if your millage is sucking take it apart and check it out. if its clogged gut it. and save up for a new one when inspection comes around. 
how do you gut the cat? also will it throw codes? cant you take the cat out and saving for when you go back through inspection and just put it back in?
If you have less than 80,000 miles on it I believe the dealer must replace it.
There was a thread on this some where.
don't gut the cat, get a new one ::)Not only is it a federal offense but the whole obd system works on the assumption the cat is working and you can foul your O2 sensors without it..... Not to mention engines run better when there is a proper amount of backpressure from the exhaust.....
If you have less than 80,000 miles on it I believe the dealer must replace it.
There was a thread on this some where.
my jeep is not on the list 
don't gut the cat, get a new one ::)Not only is it a federal offense but the whole obd system works on the assumption the cat is working and you can foul your O2 sensors without it..... Not to mention engines run better when there is a proper amount of backpressure from the exhaust.....
hey i was just curious.
<EDIT> Hypothetically speaking since it is HIGHLY illegal, I would take the cat off, ram a large metal pipe through it and bust the remaining "honeycomb" out. It takes some time but it a lot cheaper and easier than spending $200 + for a new cat. A little FYI, when they test emissions there is no way to tell if you are running a hollowed cat. They do not test for the property the cat removes, hence they just do a visual to make sure there is one there. I've heard of a really smart guy that ran his hypothetical rig for over three years with a hollowed cat and had no ill effects. My hypothetical .02 of course.
yeah the 4 cyl needs the back pressure to create power if you make it straight it will suck, also it needs the muffler.
hey i was just curious.
And I am just saying that people telling you to gut the cat on an online bulletin board is just as bad as posting they are counterfitting money... .both are illegal and both I wouldn't want to give explicit directions on how to do it in a public forum.... But that is just me
<EDIT> Hypothetical speaking since it is HIGHLY illegal, I would take the cat off, ram a large metal pipe through it and bust the remaining "honeycomb" out. It takes some time but it a lot cheaper and easier than spending $200 + for a new cat. A little FYI, when they test emissions there is no way to tell if you are running a hollowed cat. They do not test for the property the cat removes, hence they just do a visual to make sure there is one there. I've heard of a really smart guy that ran his hypothetical rig for over three years with a hollowed cat and had no ill effects. My hypothetical .02 of course.
Hypothetically Fixed.
4 banger runs fine with no cat just muffler. runs better actually my .02
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