Bad coolant temp sensor???

I pulled two pontoons out of the water for the season. I had to use 4low for the steep grade. I left it idling while hooking up and unhooking. I noticed it ran rough from the tailpipe, so I hopped in and blipped the throttle. It bogged down and then came back up and idled really rough. Almost as if it was running on 4 cylinders. I checked the gaugues and it was running pretty hot...not quite the red but way past where it normally runs. I shut her down and popped the hood to let her cool down. After about 15 minutes I fired it back up since it had cooled down to just below the 210 mark. It idled rough still but as soon as I hit the throttle it cleared out and was fine. This secenario happened twice while pulling the boats. My Auxillary fan never kicked on, but if I direct wire it to the battery it works. I'm wondering if this may be a bad coolant temp sensor and my ECU was getting a bad reading causing it to run in the open/closed loop, hence the rough running and the reason my fan didn't kick on. what do you think?

what year is your xj, and how far was it into the water idling? catalytic coverters, especially old ones, dont like water - they plug up. a plugged cat would make your xj run hotter and rough. just a thought.

-2¢

Sorry, it's a 96xj with 182k and probably original coolant temp sensor. Note*** My Heep was not in the water at all, not even my tires. It was our neighborhood boat launch and we don't have a legitimate launch ramp. I kind of dump the trailer down into the river. About 6,000 miles ago I replaced cap, rotor, plugs, and both O2 sensors. i also had a new muffler installed about 2,000 miles ago.