Hey guys,

I have a 2000 V6 and I have not been able to nail down the cause of this problem. When the temperature is above about 50 degrees the cars runs fine and doesn't throw any codes but when the temperature begins to drop the idle on the car gets worse to the point where if it's say 10 degrees I have to hold the accelerator and rev the car at about 2500 RPM until it's warm and then it runs fine. The codes I get are always bank 1 and bank 2 are too rich. I got through last winter by unplugging the MAF sensor. I did replace the MAF twice last year with a reputable part and it did not fix or even affect the issue. The engine runs good enough but not great with the MAF unplugged and i'm wondering if it could possibly be the EGR valve? Even when the temperature is warm it still seems like it doesn't idle with the power that it should as in it stalls too easily when moving from a stop (it's a 5-speed). Do you guys have any thoughts on what could be causing this?

 

May want to look at the ECT and the IAT sensors. They could be lying to the computer, and as long as it is getting a signal it won't know the difference and make improper adjustments to the fuel mixture. By unplugging the MAF you are forcing the computer to go into open loop and run on a preset program instead of making the proper adjustments.

 

Could be a bad intake air temperature (IAT) sensor, or faulty wiring. It tells the computer to richen up the air/fuel mix when the incoming air is cold, similar to how a choke richens up the mix on a carb. Without a sensor working correctly, the engine will run like crap till it warms up.

 

With the MAF sensor unplug the engine would not run great as soon as it get away from nominal. It really could be any sensor the wiring harness or even the PCM. Might want to let a mechanic take a look at it. Even if you had the equipment you would have no idea what is normal.