I have a 2007 Pontiac Torrent, which I wish I hadn’t bought because it keeps coming up with new problems every month, it seems. Besides the loud, rough ride and the spare tire well filling with water after every rain (despite the weather seal being sealed with silicone very well), it keeps coming up with engine code p0171, then the check engine light will come on, then the Stabilitrack light comes one, sometimes together, sometimes not. I’ve replaced both 02 sensors, the EGR valve and gaskets, the PCV tube that goes to the back of the engine, a new air filter, new plugs and new plug wires. It’s driving me crazy and I can’t get it to shut off. Besides throwing more cash down a hole on this thing by replacing sensors and parts til I’m broke, any ideas on how to repair this? I’ve tried shutting off the Traction Control button on the shifter plate at start up, makes no difference. This light seems to come on at random when it wants to, usually when I’m driving down a smooth interstate road, never when I hit a bump, pothole or other road imperfection. Thanks!
With all due respect, by replacing the oxygen sensors, you’re shooting the messenger(s)
p0171 is a lean air/fuel mixture code. That’s what you need to look for. Some prime examples would be low fuel pressure, intake and exhaust leaks (such as blown intake manifold gaskets)
The Stabilitrak system uses the wheel speed sensors from the ABS plus an accelerometer/yaw combo sensor and a steering wheel sensor to determine if the car is sliding and needs correction. Since the ABS warning light hasn’t come on (or has it??) it is likely not the wheelspeed sensors. So, the ABS/Stabilitrak codes need to be read to determine what the system thinks is wrong. That takes more than your basic free trouble code read at your local auto parts store.
And its likely that this has nothing to do with the P0171 code so follow @db4690 's suggestions for that problem.