Keep getting a code P0121. Throttle position range/performance

Somedays it's fine and others it's not. I've replaced it twice with 2 different sensors and I even uploaded an older tune to make sure it wasn't something in the tune after I had some idle changes made. When it's not working correctly it wants to idle at about 1500rpms and it shifts randomly. Like I will step on it and it will upshift instead of accelerate. Nothing has changed in the last month or so since this started happening. I double checked all my connections and grounds and made sure that my MAF was clean. Does anyone have any ideas as to what else this could be? I'm positive now it's not in the tune. Any suggestions on other stuff I could check or do?

 

have you tried this? https://www.performancetrucks.net/fo...ighlight=p0121