Stumped

After a day of trail riding, I was driving home on the freeway and my Jeep started to lurch and lose power. I let off on the gas and it seemed to clear itself, but then it happened again and then a few minutes later it did it again, just a cutout and then a lurch. This went on until I got home, about 70 miles later. By any chanch could I have jarred the cat material loose? Its a 98 with 120,000 miles. Any ideas. I checked the spark plug wires and it idles fine.

It could be the cat....when you're idling, do you hear any rattles coming from the catalytic converter?

I'd take a look underneath and see what's down there.

I had this problem with my 99' 4.0. After about 45 min-1 hour of driving the Jeep would start to lose power and wouldn't perform well at or over about 2,000 rpm. I drove it like this for about 3 days. I noticed one day after i put some gas in it the problem went away until I had driven about another 45min-1 hour. I had no check engine light, and it sounded good at idle. I did a fuel pressure test on it cold and after it started acting up. My fuel pressure had decreased a LOT. The fuel pump started to lose pressure after it got hot, my Jeep at the time had about 100,000 miles on it. Mine started acting up after going off road too. I'm sure mine was just coincidence, but after I replaced the pump I didn't have any more problems!
If it does turn out to be the fuel pump some of the part stores offer a pump only replacement. This is way cheaper and doesn't come with the sender, it does come with the strainer though. I'm not sure if this is your problem but I would look into it.

I had this exact problem with a 96 mustang. Bad Cat.

After a day of trail riding, I was driving home on the freeway and my Jeep started to lurch and lose power. I let off on the gas and it seemed to clear itself, but then it happened again and then a few minutes later it did it again, just a cutout and then a lurch. This went on until I got home, about 70 miles later. By any chanch could I have jarred the cat material loose? Its a 98 with 120,000 miles. Any ideas. I checked the spark plug wires and it idles fine.

Check fuel pressure!!!!!!