Cleaning a Mass Airflow Sensor (MAF)
Example is a 2000 BMW M5

There is much debate about the proper cleaning solution to use on MAFs. Some say that SimpleGreen is too agressive. The current consensus (as debated online) suggest the use of a high quality Electronics Contact Cleaner (only buy the good stuff that doesn't leave ANY residue).

The use of improperly oiled K&N air filters has been linked to premature MAF failure. Excessive oil on the filters will lead to MAF contamination.
Beware: MAFs are VERY sensitive electronics. Following these procedures might, or might not, work for your car. Some people say it works fine for a short while and then they get another Check Engine light.

This is not a cure-all. It is just an procedure that is significantly cheaper than replacing them. Try it. If it works, you could save a few hundred bucks. If not, you haven't lost anything.

If you own a BMW, and need new MAFs, you should do some research online. Apparently VW sells the same Bosch part for much, much less than BMW.
I don't claim to be an expert. Do this at your own risk. Do some research. I posted this for my M5 buddies. And now, several hundred of you a day come to my little site in search of knowledge. Thanks. I hope it works.

Feel free to visit an Advertisement "Sponsor" to help support the bandwidth.

Please don't "deep link" into these photos. Or I'll need to change their names.
the first of 2 Air Cleaners & MAFs
Starting on the first of 2 Air Cleaners & MAFs
Cleaning Tools - Choose your cleaning solutions carefully
Cleaning Tools - Choose your cleaning solutions carefully. Electronic Contact Cleaners, "MAF Cleaners", 99% Isopropyl Alcohol, and maybe Simple Green.
Torx T20 Security
Torx T20 Security - I needed a 6-point security Torx (available at most Auto Parts stores). Later cars used a 5-point security Torx. (much harder to find)
Loosen pipe clamp
Loosen pipe clamp
Unplug the wiring harness
Unplug the wiring harness
Pop off the 4 clips from the air cleaner
Pop off the 4 clips from the air cleaner
Lift the Air Cleaner Slide it and MAF towards outside of car
Lift the Air Cleaner Slide it and MAF towards outside of car
Pop off these 2 clips (one underneath)
Pop off these 2 clips (one underneath)
Unscrew with T20 Security Torx
Unscrew with T20 Security Torx (5 or 6 point, whichever you need). In a pinch you can use needle-nose pliers... very carefully.
Dip this end in Simple Green 1:1 solution
Dip this end in Simple Green 1:1 solution. Or spray liberally with electronics Contact Cleaner.
Clean gently with q-tips
Clean GENTLY with q-tips. Very gently. As if the health of your entire car depended on your gentle touch.
Shake off and dip into 99% alchohol
Shake off and dip into 99% alchohol. Don't use 70% alcohol. You want the pure stuff.
Dip mesh end in Simple Green and then Alcohol
Dip mesh end in Simple Green and then Alcohol. Or use Contact Cleaner & then Alcohol.
Screw clean sensor back into tube
Screw clean sensor back into tube.
Clean these gaskets, then lubricate with Vaseline
Clean these gaskets, then lubricate lightly with Vaseline. (this applies to this BMW, I have no knowledge of what your particular car might need for lubrication.)
Clean tube and Replace flat gasket here
Clean tube and Replace flat gasket here
Clean and Replace round gasket here
Clean and Replace round gasket here
Reassemble, clip in, point plug towards rear
Reassemble, clip in, point plug towards rear
Slide in the tube first, then...
Slide in the tube first, then...
...drop in air cleaner
...drop in air cleaner
Tighten pipe clamp and fasten clips. Done.
Tighten pipe clamp and fasten clips. Done.