Hey there, I've been having some issues w/ my 2008 Grand Prix GXP.
I had a reduced engine power mode come up while at a traffic light, and limped into a gas station.
Put in a full tank of gas, and got out of limp mode, but the Check Engine light still remained.
A few days later, the check engine light went out, and everything seemed normal.
A few days after that, and upon starting the car in the morning, the car went straight into reduced power mode. After turning the car on and off again about half a dozen times, it finally removed the reduced power mode, and was drivable, but the check engine light remained.
Took it to a mechanic, who scanned the check engine light, and came up with a 2122 code.
He cleaned the throttle body, and replaced the electronic gas pedal.
Car ran good for a day, but then the next morning, still the same problem, starts up into reduced power mode.
I did the same thing as before, on and off again until removing the reduced power, and it was driveable again.
It seems to only go into reduced power mode on start up if the car has been sitting over night.
I've also found just to let the car idle for about 15 minutes, until the water temp is up, and then turn the car off, and on again, this takes it out of reduced power mode.
Took it back to the mechanic again, and he replaced the throttle body.
The car seemed to run fine again, until again, the next morning.
I'm not rushing back to the mechanic to throw more parts and money into it before I have a good idea of what is actually going on.
The car runs fine after getting it out of reduced engine power mode, however, just the idling for 15-20 minutes before I have to go anywhere is a pain in the arse, and isn't exactly fixing anything.
Does anyone have experience with this?
It seems like quite the common issue, but the fix for it seems to vary.
Trying to plan my next steps before I go spending more money, as dropping $700 on my car in a week certainly hurts the budget.
Would my next step be checking the voltage on the ECM?
Or would it be a throttle position sensor, throttle position actuator, or throttle actuator control motor?
Is there a way for me to check these things out on my own without taking it to another mechanic?
