terzdesign

My check engine light came on the other day and code P0121 came up. 99 xj sport I6.

I ran some voltage and ohm tests on the sensor. What I know:

-On pin 2, I get .83dcv at idle and 4.05dcv at WOT. Those seem to be registering within spec.
-The +5 wire is registering 5.5 volts.
-The ground wire opposite is reading 12.3dcv.
-ohms test on the middle and passenger side sensor prongs without the harness attached show .86 when closed, and 3.93 WOT; and a gradual change of that in between when the throttle is pulled.

This all leads me to believe the TPS is in working order. The only symptoms I have noticed are when the CEL came on. I was on the highway going 70 with cruise. When I let off of cruise with the brake, the engine RPM shot up for a moment, like it downshifted for whatever reason. Then it gave me trouble like the engine didn't want to respond to additional throttle.

I would rather not drop $100 on a new sensor if it's not broken. I heard rumors that the clockspring might be at fault but couldn't find anything conclusive on an XJ search. Anybody had trouble like this? I posted in Jeepforums as well just in case.