A Mass Air Flow (MAF) sensor monitors the temperature and weight of air entering your engine. Your onboard computer needs that information to calculate the right amount of fuel for all engine operating conditions.
The sensor works by heating a delicate platinum wire or plate and measuring the current required to keep it at a constant temperature while air blows past it. Over time, dust and oil particles stick to the hot wire/plate and bake on. Eventually, those baked-on particles insulate the wire/plate from the airstream. This causes starting, idling and acceleration problems, as well as poor gas mileage.
Carmakers recommend that you replace the MAF sensor ($300) at that point. But if you clean your car's MAF sensor regularly, you can avoid that $300 repair and keep your engine running at top efficiency. The cleaner only costs about $7! We recommend that you clean the MAF sensor every time you change your air filter. Here's how:
Before going to the store, pull off the air duct between the air filter box and the throttle body to see how the MAF sensor is anchored. If you see Torx screws, buy a Torx tool and a can of CRC Mass Air Flow Sensor Cleaner. Don't use any other cleaners; they can ruin the MAF. Everything you need is available at CarQuest, Advance and O'Reilly auto parts stores.
With cleaner and tools in hand, locate the MAF sensor in the air duct between the air filter box and the throttle body. Before you remove the sensor, use a digital camera to record the sensor setup and connections for reference later. Carefully remove the sensor from the air duct and disconnect the electrical connector.
Spray 10 to 15 spurts of the cleaner onto the wire or plate. Don't scrub the parts; you may break the wire or damage the plate. Allow the MAF sensor to dry completely before reinstalling it in the air duct.