How to Clean a Dirty Mass Airflow Sensor

  • 1-3 hours
  • Beginner
  • 5-15
What You'll Need
Dirty mass air flow sensor
Cleaning solution (isopropyl alcohol, carb cleaner, or some similar compound)
Container (plastic bag, five gallon bucket or other type of container)
Towel or other absorbent layer

A mass airflow sensor helps provide a good fuel mix by monitoring the amount of air coming into the engine. On some vehicles, the mass airflow sensor replaces the MAP or manifold air pressure sensor. These types of sensors are critical for helping an engine to run well. When they become dirty, all of the calculations of the engine computer can be thrown off, and according to some mechanics, a dirty mass airflow sensor can cause the engine computer to set a “Lean” code, where it is reporting a lean fuel mix. To prevent these kinds of issues, it's a good idea to clean a mass airflow sensor periodically.

Step 1 - Locate Your Mass Airflow Sensor

The exact location of a mass airflow sensor varies according to your vehicle model. Experienced mechanics report that it is usually connected to the air intake, which makes sense, since it needs to be correctly positioned to report on the air coming into the engine. Check your owner’s manual or supporting documentation to find your mass airflow sensor, which may be housed in a plastic container.

Step 2 - Disconnect the Mass Airflow Sensor

Disconnecting the mass airflow sensor may vary according to the model of your vehicle. Remember what you are doing in order to reinstall the part later. Check the owner's manual for specific information on bolts or other fastening setups.

Step 3 - Fill the Container with the Cleaning Compound

If you're using a bucket, fill the bucket to the point that the mass airflow sensor can be fully submerged. If you're using a bag, the same applies, though you can get cleaning results with a little less liquid if necessary.

Step 4 - Add the Mass Airflow Sensor

Place the mass airflow sensor in the bag or bucket and move it vigorously so that the small contaminants are shaken out.

Step 5 - Dry the Mass Airflow Sensor

After you've thoroughly cleaned the sensor, make sure that it dries thoroughly. Just like with other parts, you don't want to introduce it back into its environment when it is still wet. You can effectively dry out the part by leaving it for an appropriate period of time in a warm dry setting, on top of some kind of absorbent material like a chamois or towel. However, you choose to do this, it's critical to dry the part thoroughly. After the mass airflow sensor has dried, replacing it will require back-tracing the steps you took to disconnect it, generally using a few bolts and/or screws.

Doing Your Own Engine and Vehicle Maintenance

Cleaning a mass airflow sensor is a lot like other kinds of similar vehicle maintenance. The simple process described above, (uninstalling, cleaning, drying, reinstalling) can be done with lots of other car parts. When you take the time to assemble the materials and develop the practical skills necessary to clean and maintain your engine parts, you are more likely to take on a greater share of periodic maintenance for your vehicle, and save a lot of money on replacement parts and shop costs.