Introducing Your Mass Air Flow Sensor
One of the key auto parts in the electronic fuel injection system, the mass air flow sensor or air flow meter sensor measures the amount of air flowing into the engine. When looking for this car part, look in-between the intake manifold and air filter in the engine. Modern cars have their intake air temperature (IAT) built into the MAF. Most modern cars use a hot-wire type mass air flow sensor.
The hot-wire sensor gets the name from a small electrically heated wire. When the engine idles, a little bit of air flows around the wire to keep it at a comfortable temperature. The electric current in the wiring increases when there is more airflow. A small electronic chip inside the MAF sends a digital signal about the electric current to the engine computer. The engine then decides how much fuel to inject based on the air flow to keep air and fuel balanced.
What Causes Your Mass Air Flow Sensor to Go Bad?
The MAF sensor can be contaminated or damaged if the air filter is not installed correctly. Debris can be sucked into the sensor during air filter replacements. Other causes include a collapsed mass air flow sensor or one that is improperly installed. Soaking your air filter for too long can also produce issues with your MAF sensor.
Mass Air Flow Sensor: Bad Symptoms
A faulty MAF sensor cannot correctly determine the amount of air causing the engine computer to miscalculate the fuel needed. Some signs of a bad mass air flow sensor are no-starts, stalling, lack of power, and acceleration. The check engine or service light may turn on with a faulty mass air flow sensor. If the light to check your engine turns on, an error code can be retrieved from your car with a scanning tool.
Here are a few codes associated with a bad MAF.
- P0100 - Mass Air Flow Circuit Malfunction
- P0101 - Mass Air Flow Circuit Range and Performance
- P0102 - Mass Air Flow Circuit Low
- P0103 - Mass Air Flow Circuit High
- P0104 - Mass Air Flow Circuit Intermittent
These codes may not work for your vehicle. Check what the exact codes of your make and model are for a faulty MAF sensor.
How do I test my Mass Air Flow Sensor?
The only way to test a modern car’s MAF sensor is to use a scan tool that measures RPMs. Normal readings (measured at idle) are 1,000 RPM to 3,000 RPM. A damaged mass air flow sensor will show lower reading than normal. The air flow in V6 or V8 may show higher readings due to engine volume, even with a malfunctioning MAF sensor.
Low readings do not always mean that your sensor is faulty. Mechanics use diagnostic tools to determine which car part has a problem.
For Home Testing, download a scanner for your phone that tests your car like the Torque App. You will need a Bluetooth adapter that links to the OBD connector. Inspect the terminals and wires carefully to make sure that your readings are not caused by electrical connection.
Should I Fix or Replace My Sensor?
In some cases, you can fix the issue by cleaning your sensor. This procedure is delicate and usually only works for short fixes. We recommend replacing your MAF sensor to be sure that the problem is resolved. Check out our selection of mass air flow sensors.