Erractic Idle

[kitchensta]

I have a 2007 Tahoe. I got a message that the throttle sensors were needing cleaned or such...P0121 was the code. Anyways, we cleaned the throttle body ourselves and when we went to start the vehicle it revved up to like 4000 RPM and would not go down. It finally went down but would go back and forth. My husband was able to put it in gear once it went down to normal but when you go to stop if you don't have your foot on that brake you are going to be blasting off. Any thoughts on how to fix this....

 

[txss]

I have seen the same thing. And now my gas mileage has tanked after cleaning the MAF. What were was your final result? Did you replace it? Clean it? Just curious. I am about to replace my MAF.

 

[pavet12]

Since you disconnected the throttle body you need to find a mechanic with a Tech 2 tool to reset the idle or take it to a GM Dealer. There is an alternate method that I tried but it didn't work. Some say if you drive at speeds above 70mph for a while and then back down to stop it will re-learn. Best of luck.

 

[poncho07hoe]

i had the same problem i ended up taking the truck to the dealer they charged me $90 dollars to reprogram the throttle everything was fine after

 

[clkelley]

That seems odd, I have removed and cleaned many MAF sensors and throttle bodies without any issues. If I may ask, what did you use to clean the MAF and throttle body?

 

[txss]

I agree with clkelly - I have done this multiple times, no dealer was needed and idle returned to normal. However in my case, I still have the P0121 problem so who cares what I say anyway :whymewhyme:

 

[clkelley]

P0121 is a throttle position sensor code. I personally would unplug it and clean the plug itself at the sensor and add some dielectric grease to it and see if that helps. You may also want to put some dielectric grease on the plug at the MAF as well and make sure all the wires into the plug are fully seated in the plug and that there is no moisture in it.

 

[Sales @ CAI Inc]

You may even want to replace the TPS, pretty quick, cheap and easy. If you still have the issue at least you know that was not it. I replaced it on my Sierra 2500HD and it took all of 5-10 minutes. Good Luck!