08 Gmc Sierra 1500 5.3L

[Neal29]

I have a 2008 GMC sierra 1500 5.3L, the truck will not stay on idle for more than 15 mins. It will shut off and say engine power reduced and will say service stabilitrak. I have to wait for like 5 mins then try to turn it back on again. It has shut off on me while driving which can very dangerous. Asking for help on what could be wrong and what I need to replace. It only has 111k miles on it. It makes it very hard to stop at traffic lights and drive thrus for food. I have been told it could be the alternator or O2 sensor, but I am open to any other suggestions. Please and Thank you! 

[dsr611]

CEL on?  If so, what are the codes it throwing?

 

If it's the alternator, it should give you a warning on the instrument panel/DIC of low voltage, battery low, etc.  If it's O2 sensors, it should be throwing the CEL...you need to get the codes read and repost what they are.

[Neal29]

Alright thank you will do! 

[Christoph]

Good morning Neal. Have a 2010 1500 Silverado 5.3. Two years ago had 92000 miles on it. First my cruise control stopped working, then right after that had the reduced power mode came on with check engine light. Threw code P2135. Cleaned throttle body, it was dirty still did nothing and would randomly go back into reduced power mode. Did some research and yes Gm had major issues with the throttle position sensors on most vortec engines years 07-11. So I just changed my throttle body which has a new throttle body poisoning sensor right on it. Had my local delership perform a idel re-learn and was good to go. Hope this helps you out Neal. 

Edited May 9, 2021 by Christoph

[Neal29]

Thank you so much! I will go ahead and try that to see if that will do the job! Cheers