The MAF (Mass Air Flow) sensor sits in the air intake tube, usually near the air cleaner. Its job is to measure the amount of air flowing into the engine. The PCM (Powertrain Control Module) then uses this information along with information from various other sensors to calculate the fuel and ignition settings for a smooth running, fuel efficient engine.

Over time the sensing prongs of the MAF sensor can get dirty and the sensors accuracy will deteriorate; this is especially true if you use an oil type air filter such as a K&N.

A dirty MAF sensor can give some peculiar drivability problems and will not necessarily set a fault code or illuminate the "Check Engine" light.



EQUIPMENT REQUIRED

• 1 TPX-20 Tamperproof Torx driver
• 1 Can of electrical cleaner (or similar)

First unplug the wiring harness circled in green in the picture above. Then using your Torx driver undo the two securing screws circled in red. Now very carefully lift the MAF sensor out of its housing.


The picture above shows the two sensing prongs of the MAF sensor. They should be shiny and silver but probably look a little tarnished. Carefully spray your electrical cleaner at the sensing prongs to wash off the dirt, but DO NOT touch or brush these prongs (when thoroughly cleansed they should be bright silver). Allow to dry before refitting and make sure the sealing O-ring is correctly seated in the MAF housing. The picture below shows the MAF sensor sealing O-ring on my fingertip and the groove in the sensor housing that it fits into is circled in red.


Carefully lower the MAF sensor into its housing; just "nip" the two securing screws tight (do not over tighten) then reconnect the wiring harness and the job is done.



This job only takes a few minutes and could be incorporated into your service schedule every 15,000 miles.



Happy motoring!


Dereck