Reduced power output and engine ping

After driving another XJ, I noticed mine was down on power, and when we are out playing in the mud, it bogs down to about 3,000rpm with only 31's and starts pinging really badly.

Any common problems associated with this?

What year is your rig. Jeep had a tsb for engine pinging that required the pcm to be programed.

1997

Possibly clogged cat?

Cat was removed. I thought the same thing. I've seafoamed it since the last outing, so hopefully that will help. Next step is a compression test, followed by running a second windshield washer pump that squirts it into the throttle body at WOT to ease up on the preignition (I'm going to try it anyway to see if theres a power gain from it).