Hey dudes so my 2008 Silverado threw this code last night, P0121 TPS throttle position sensor. Anyways, i called a local chevy dealer and i explained to the tech what was happening. I had an idle of 1,500RPM while in park as soon as i shifted into drive or reverse it would be normal. I also asked if i was able to change out the TPS, he said no. He told me that i needed to replace the entire TB assembly. I just want clarification on this issue. Am i going after the right problem or is it something else wrong with the truck? And also, is the tech correct on me having to buy a new TB? thanks guys!

 

Tech was telling the truth but you can try cleaning the TB first if you like.

 

Thanks for replying dude, I actually did clean it out. I didnt use a cleaner but I just wiped it down with a rag. Funny think is after I cleaned it, the RPM's shot up to 1,500 and I couldnt bring her down to a normal idle.

 

Try putting a few miles on it and see if the high idle and SEL clear themselves.

 

Kool thanks Rob, I apprecite the input.

 

yeah unplug your battery your battery for 30mins. Start your truck and push emergency brake all the way down. Put in drive with ac off and let idle for 5 mins. Then do the same with ac on for 5 mins. Then after 200 miles max it should have relearned its settings. If that doesn't solve your problem you can buy a LS7 TB off ebay for 150.

 

Nekroman, I forgot to ask you how many miles you have on that rig. The throttle body is covered by the 5yr 100k mile warranty. Im sorry I forgot to tell you that.