Hope Someone Can Help - "Reduced Engine Power" 2007 G Prix

[alanb]

I'm having an issue with my 07 GP. This can happen over a period of a few days or may not happen for a month. After driving for usually more than 30 minutes the engine light will come on, I hear warning chimes and the display flashes REDUCED ENGINE POWER. This has happened about 10 times in the last 4 months. Also, it always happens at a stop, never when the car is in motion and always when the car is at full operating temperature. It does seem to happen while stuck in bumper to bumper traffic which is why I seem to think it may have to do with something possibly heating up.Just before the engine light comes on, the idle will increase approx. 400-500 RPM. Car goes into limp mode, no response from accelerator pedal and idles very rough at around 1500 RPM.

So I let the car sit for 5 minutes... repeatedly turn the ignition on and off a few times and it starts up. I go on my merry way car drives perfect and it does not do it again. Engine light will stay on for a while then goes off. This may happen again the next day or not for a month.
Engine code P0507- idle air control higher than expected. Now i've read of other people having similar issues but able to still drive the car at a reduced speed.I can put my pedal to the floor with absolutely no response. Also the car doesn't stall out, will just shake, rattle and roll...

I love the car. My 5th GP but if I can't get to the bottom of this, she goes up for sale. Really hoping someone can help me with this.

 

[Scottydoggs]

A P0507 DTC trouble code may be caused by one or more of the following: A vacuum leak Leaking air intake after the throttle body EGR valve leaking vacuum A faulty positive crankcase ventilation (PCV) valve Damaged/failed/dirty throttle body Failed EVAP system Failed IAC (idle air controller) or faulty IAC circuit

Possible Solutions
This DTC is more of an informational code, so if there are any other codes set, diagnose them first. If there are no other codes, inspect the intake air system for air or vacuum leaks and damage. If there are no symptoms other than the DTC itself, just clear the code and see whether it returns.

If you have an advanced scan tool that can interact with the car, command the idle higher and lower to see if the engine responds appropriately. Also check the PCV valve to see if it's blocked and needs to be replaced. Check the IAC (idle air controller) if equipped, verify it's operation. If available, try swapping in a new throttle body to see if that fixes the problem. On Nissan Altimas and possibly other vehicles the problem may be fixed by having the dealer perform an idle air relearn procedure, or other relearn procedures.

Read more at: http://www.obd-codes.com/p0507
Copyright OBD-Codes.com

 

[Fivefingerdeathpunch]

I'd blame the APP or the throttle body as possiblities.

Remove the TB and clean it and the electrical connector, inspect the plug down at the APP too.

 

[Mirraco]

Is the engine over heating at all? I had a 04 gp, I put coolant elbows on it, drove it and had a air bubble so it ran all way to the red, car was beeping and engine light came on, it also said turned ac off because engine was hot? Thats only thing i have had close to that.