bow07

Fixed

Ok well after all of this I think I found the probelm to be a vacuum leak. What is supposed to attach to the black thing coming off the intake on the passenger side? Is it just supposed to have a cover on it? Thanks

Yeah I am going on tuesday so they can replace my grille (because they broke it) so I will have them check it then.

Well the dealer has replaced the Yaw sensor and the Mass Air sensor to no avail. I just checked the fuel pressure today and while idling it is only around 45-50psi. If you give it gas it drops real fast then goes back to the 45-50. This is low correct? So the fuel pump may be the problem?

Thanks for looking up the info. The thing is I have not had any work done on the truck (except the heated washer recall back in November). I posted the temp and weather outside because if I park the truck in the garage for a whole day and let it warm up and dry out, the ses light goes off. This only seems to be happening when it is below freezing out. The stabilitrak light comes on only when I am stopped (regardless if the ses light is on or not) and it is very intermittent. I just cleaned the MAF so I'll see if it does anything. Thanks

You haven't changed fuel types lately have you? For example 87 Octane to E-85....I had these same issues a while back after a Fuel Switch and I guess I didn't drive it long enough to let the computer relearn the Fuel Type, and the dealer said it will run horribly unless you drain the fuel and then reprogram the computer.....however I think you already had your computer reprogrammed... No I have not, I dont have the flex-fuel engine.

New Body Style 5.3L I have checked all the vaccum lines for leaks and found none. I am starting to think that it may the MAF sensor, but I dont have the tools to check it. It could have something to do with the stabilitrak issues as well (b/c if you unplug the MAF it throws the same stabilitrak and traction control warnings.) Is anyone else having these stabilitrak problems??? These codes seem odd since my truck has so few miles. Good thing all this is under warranty

My truck has been throwing the P0171 and P0174 dtc for the past 3 weeks. Also, I have been having issues with a Service Stabilitrak / Traction Control light coming on. It will come on when I am setting at a stoplight and stay on until I get going or it shifts into 2nd (which causes an extrememly hard shift when the light is on). I took it to the dealer last week (but the ses light went off that morning go figure) and they checked the intake for leaks and just re-programmed the computer. They also ordered a new Yaw Rate sensor for the stabilitrak issue. Anyways, after I left the dealer the light ses came back on and I was curious if anyone else has experienced these problems and what they did to fix them. (The yaw sensor comes in next week and I want some ideas to give the dealer when I take it back in) Truck: 2007 Sierra 4wd Crew Cab; approx 16,000 miles; factory tune; GMPP Intake and Exhaust. (temps have been in the 20's and snow) Thanks for any information in advance!