Unlikely it's the cat then. Gap the plugs, change the fuel and air filters, check/clean the cap/wires. Look/listen for vacuum leaks? It's stuff you need to do anyway, then if that doesn't help you can rule it out.

Did you change your suspension, gears or tires before it lost power? D.

Also, I've seen U-Joints stiff out of the box, they will loosen up soon enough!

 

sorry about that, I am keeping it OEM as of right now, just basically replacing parts at this point. I don't know much about the gears (or much else) but I am going to get all the info on my jeep so I can post it. I am sure people like me are annoying on this forum so I am going to get as much info as I can prior to posting questions. thanks for all the replies.