How to Clean a Mass Air Flow Sensor

Your engine needs the proper air/fuel ratio to run correctly. The Mass Air Flow (MAF) sensor plays a critical role within the fuel management system to ensure the ratio is correct. The MAF sensor monitors the temperature and amount of air entering your engine.

This information is sent to the car’s computer which controls the fuel injection and ignition systems. If the MAF sensor becomes dirty inside and/or begins to fail, you’ll notice issues like longer cranking time when starting the engine, hesitation or jerking when you accelerate, rough idling or stalling and sometimes black soot/smoke exiting the tailpipe. You also may notice a decrease in fuel efficiency.

Cleaning the MAF as part of regular routine maintenance can help reduce and/or prevent these problems. If the MAF sensor is at fault, cleaning it can help, and many times, even solve the problem. This can be done at home. You just need to remove the component, clean it, and reattach it to your engine air intake system. A few basic supplies will be needed (some hand tools and special cleaner), all of which you can find at your local AutoZone.

Check if your car has a Karman-Vortex air flow sensor. These are found in some Toyota, Mitsubishi, and Lexus vehicles and can’t be cleaned with MAF Sensor Cleaner.

How to Clean a Mass Air Flow Sensor

1

Unplug the Sensor

Turn the engine off, remove the keys from the ignition, and let the engine cool. Locate the mass air flow sensor by consulting your owner's manual. Unplug the part from the vehicle's electrical system.

2

Remove the Sensor

With the sensor unplugged, loosen the clamps and any brackets holding it in place. Slide the sensor assembly away from the tubing and carefully remove from the air intake boot(s).

3

Clean the Sensor

Place the sensor on a towel for cleaning. Apply the cleaner — 10-15 blasts around the inside of the sensor will do. Also clean the sides of the part, its housing, its connectors, and its terminals. If you have a hot wire mass air flow sensor, make sure the cleaner doesn't get onto the hot wires or plate.

4

Reattach the Sensor

Allow the sensor to dry. This should only take a few seconds. Once the part is ready, you can re-install it back into place, reattach and tighten the clamps/brackets. Once you've re-installed the sensor, wait a few minutes before starting the vehicle to ensure the cleaning chemicals have evaporated.

5

How Often Should You Clean the Air Flow Sensor

It's safe to clean the sensor every time you change the air filter. The job is simple enough to be a part of your routine maintenance. If your check engine light comes on and there's a trouble-code related to the MAF, that would definitely be a good time to clean the sensor. This simple maintenance step can easily be performed in your garage whenever you have a few minutes to spare. In addition to fixing problems you've had with your engine running or idling roughly, cleaning the mass air flow sensor can help improve your gas mileage and maintain drivability performance.

Advice, how-to guides, and car care information featured on AutoZone.com and AutoZone Advice & How-To’s are presented as helpful resources for general maintenance and automotive repairs from a general perspective only and should be used at your own risk. Information is accurate and true to the best of AutoZone’s knowledge, however, there may be omissions, errors or mistakes.

Be sure to consult your owner’s manual, a repair guide, an AutoZoner at a store near you, or a licensed, professional mechanic for vehicle-specific repair information. Refer to the service manual for specific diagnostic, repair and tool information for your particular vehicle. Always chock your wheels prior to lifting a vehicle. Always disconnect the negative battery cable before servicing an electrical application on the vehicle to protect its electrical circuits in the event that a wire is accidentally pierced or grounded. Use caution when working with automotive batteries. Sulfuric acid is caustic and can burn clothing and skin or cause blindness. Always wear gloves and safety glasses and other personal protection equipment, and work in a well-ventilated area. Should electrolyte get on your body or clothing, neutralize it immediately with a solution of baking soda and water. Do not wear ties or loose clothing when working on your vehicle.

FREE Loan-A-Tool® program requires returnable deposit. Please note that the tool that you receive after placing an online order may be in a used but operable condition due to the nature of the Loan-A-Tool® program.