According to some Toyota forums, cleaning Mass Air Flow (MAF) Sensor can fix low idling. At about 85,000 miles my Corolla’s idle speed decreased from 700 to about 500rpm and felt like it was going to stall sometimes after the AC compressor kicked off. Cleaning the MAF sensor seemed to have done the trick and it was a simple procedure that took no more than five minutes.
- Spray can of electronic components cleaner.
- Philips head screw driver.
[step 1] Locate the MAF sensor on the air filter box in the engine compartment. Disconnect the electrical connector and remove two Phillips head screws holding the sensor in place. Now wiggle it out carefully.
[step 2] Liberally spray cleaner over the visible sensor (but be careful not to touch it with your hands) until any dust buildup has been removed.
If you look inside the bottom opening of the component (where the circular hole is), there is a 2nd sensor deep inside the plastic housing. Spray cleaner into the housing to remove dust from this sensor as well, but be careful not to touch the sensor with the straw of the spray can, it can easily be broken or damaged.
[step 3] Let the MAF sensor dry for a few minutes and re-install.
That’s it. Hope it helps someone else.