Wont idle right.Idles at 2000 rpm then drops to 900 or less then usually will stall.If i unplug the mass air sensor while it is running nothing changes. Does this mean it is bad? Thanks,John

This is normally caused by a dirty sticking throttle plate and if you check the back side of the throttle plate and it is gu-ey and has black varnish on it then you need to clean the plate and the plate hole. Also A EGR valve can cause the idling problem. If the Mass air flow sensor was bad it would run really bad and if you unplugged it it would die. So try cleaning the EGR valve and throttle plate first. The Maf or mass flow sensor does three things one determines air baromertic pressure Dinsity of the air and the temprature of the air and air flow flowing threw the engine. The throttle postion sensor could also be defective, you could disconnet it and it should go into limp in mode and should run with out showing the symptoms you discribed. hope thsi helps. Aslo the Fuel evaperator canister check valve could be stuck open or you could have an intake leak. If you need the information to test that let me know and I will post the solution.

MAF concerns the proper mixture of fuel, not the idle speed, so it is most likely all right (if it wasn't, your car would die before it reached 2000 RPM's). Idle speed is controlled by a small motor, generally mounted around the throttle plate. This is controlled by a computer, which judges idle requirements by the input from crank or camshaft position sensors. Make sure that all of your sensors are clean, and in proper operation.