How to Repair a Mass Air Flow Sensor

by Alibaster Smith

A mass air flow sensor monitors the air coming in through the air intake system so that the vehicle's electronic control unit (ECU) can make adjustments to the air/fuel ratio. Adjustments to the fuel mixture are necessary to keep a vehicle running smoothly. Too much air and not enough fuel will cause the engine to run lean, causing the vehicle to potentially stall. Too much fuel, however, and not enough air will cause the engine to run rich, reducing fuel economy. The perfect air/fuel ratio is 14.7:1 or 14.7 parts air to 1 part gasoline. When your mass air flow sensor fails or is about to fail, your vehicle will have a hard time running. It may stall constantly, even when you're driving. The sensor, however, may not be broken. Instead, it may just need to be cleared of any dust or debris that has gotten into the intake system.

Step 1

Open the hood of your vehicle and locate the mass air flow sensor on or near the larger air cleaner box.

Step 2

Remove the the two screws that hold the mass air flow sensor to the intake system.

Step 3

Pull the mass air flow sensor out of the intake.

Step 4

Spray the platinum sensor wires at the bottom of the "neck" of the mass air flow sensor that sits in the intake system with the electronic parts cleaner. This will remove any dust or debris that may have gotten into the sensor and is causing the sensor to malfunction.