A mass airflow sensor, or MAF for short, is found almost exclusively on fuel injected engines. A MAF is an electronic device that runs between your vehicle’s airbox and intake manifold. It measures the amount of air that passes through it, and sends this information to the engine’s computer, or ECU. The ECU takes this information and combines it with air intake temperature data to help determine the proper amount of fuel necessary for an optimal combustion. If your vehicle’s MAF sensor is failing, you will notice rough idling and the vehicle running rich.
Part 1 of 1: Replacing the bad MAF sensor
- Replacement mass airflow sensor
Step 1: Disconnect the electrical connector from the mass air flow sensor. Squeeze the tab on the harness side of the electrical connector while firmly pulling on the connector.
Keep in mind, the older the vehicle, the more stubborn these connectors can be.
Remember, do not pull on the wires, only the connector itself. It helps to use gloves with a rubberized coating if your hands are slipping off the connector.
Step 2: Disconnect the mass air flow sensor. Use a screwdriver to loosen the clamp or screws on each side of the MAF that secure it to the intake pipe and air filter. Once the clamps are removed, you should be able to pull the MAF right out.
- Tip: There are many different ways a MAF sensor is secured. Some have screws that hold it to an adapter plate which attaches directly to the airbox. Some have clamps that hold the sensor in-line of the intake pipe. When you obtain your replacement MAF sensor, note the type of connections it uses and make sure to have the appropriate tools to disconnect and reconnect the sensor to the airbox and intake pipe.
Step 3: Connect the new mass airflow sensor. The sensor slides into the intake and then is clamped on.
On the airbox side, it may reconnect with bolts or it may be the same as the intake side, depending on your particular vehicle.
Make sure all the clamps and screws are snug, but do not overtighten them as the sensor is plastic and can break if handled too roughly.
- Warning: Use extra care to not touch the element of the sensor on the inside of the MAF. The element will be exposed when the sensor is removed and it is very delicate.
Step 4: Reconnect the electrical connector. Reconnect the electrical connector to the new mass airflow sensor by sliding the female side of the connector over the male side that is attached to the sensor. Press firmly until you hear a click that indicates the connector is seated all the way and locked into position.
At this point, double check all your work to make sure you haven’t left anything loose and the job is complete.
If this job seems like more than you are willing to attempt, a qualified technician from YourMechanic can come to your home or office to replace the mass airflow sensor for you.
This article originally appeared on YourMechanic.com as How to Replace a Mass Airflow Sensor and was authored by Michael France.