I've been getting a check engine light. My FIXD OBD-II Active Car Health Monitor was showing a P0121 code and says it's a serious problem. I replaced my throttle position sensor with a Duralast TPS4270 from Autozone. Now the engine idles between 2000 and 2500 RPMs. Prior to replacing the sensor the truck was running perfect with the exception of the check engine light. Any suggestions?

 

either pull the battery for a while, or just drive it a while. The ECU needs to relearn the TPS system. Mine took about a week of normal driving.

 

The other option is to take it to a shop and have the learn programming performed...

 

Relearn procedure:
After I posted this question here I found this video on youtube. What did I ever do without youtube! Apparently it takes a while for the truck's computer to relearn the position of the throttle.(When I replaced the sensor I cleaned the carbon buildup off the throttle body. Made it shine like new!) After trying the 3 minute idle, 1 minute off, 3 minute idle procedure several times and driving it around over 44 mph several times with no success, I let it sit over night and the problem fixed itself. Wish all my mechanical problems resolved themselves that way.

 

Right... just like I said... drive it for a while... it learns. It's by design.