4 Signs Your Mass Air Flow Sensor is Failing

Reading Time: 3 minutes

Fuel efficiency has become a major consideration when purchasing a vehicle. With gas prices rising, every drop of fuel counts. While driving style greatly affects fuel efficiency, maintaining your car’s engine can help you squeeze every mile out of your fuel tank.

A combination of parts works to achieve the best performance using the least amount of fuel. The mass air flow sensor is a small part that is largely responsible for the clean and efficient burning of fuels by our vehicles.

The mass air flow sensor monitors the volume and density of air entering your car’s engine through the intake.

What is a Mass Air Flow Sensor?

The mass air flow sensor monitors the volume and density of air entering the engine through the intake. It then sends the data to the engine control unit (ECU). Based on this data, the ECU directs the fuel injection system to achieve the ideal air-fuel mixture as demanded.

The accuracy of the mass air flow sensor is critical to getting your car to run properly. It is also responsible for adjusting the amount of fuel delivered to the engine for better efficiency. A faulty sensor can result in a significant loss in power, poor gas mileage, and frequent engine stalls.

What are the symptoms of a failing Mass Air Flow Sensor?

The Check Engine Light is on

Since the mass air flow sensor is a major part of the powertrain management, the check engine light will light up if damage or dirt affects its readings.

Rough idle and engine stalling

A malfunctioning mass air flow sensor will send the wrong airflow information to the engine’s computer. The computer will compensate for the lack of information and deliver too little fuel, making the idle rough and stalling out the engine at times.

A faulty mass airflow sensor will send wrong airflow information to your engine’s computer that can cause rough idle or stalling out.

Poor engine performance

When you suddenly accelerate in a car with a bad mass air flow sensor, the lack of information about the fuel and air mixture from the sensor will make the computer look to other sensors for data. It will take half a second or so for the computer to gather the data required to increase the fuel flow.

Poor fuel economy

Too much fuel delivered into the cylinders of the engine will cause your engine to run too rich. Even when you aren’t pushing your car’s engine, the fuel pump will deliver the same amount of fuel to the engine instead of optimizing delivery for maximum efficiency.

How do I know the Mass Air Flow Sensor is my car’s problem?

Checking your car’s mass air flow sensor is quite simple. You can find it in your engine compartment, generally near the piping of the air box.

Inspect the mass air flow sensor from physical damage and dirt. A dirty sensor can trigger incorrect readings. If dirt is present, spray some mass air flow cleaner onto the wire or plate. Do not scrub the parts because it may break the wire or damage the plate. Before reinstalling the mass air flow sensor, allow it to completely dry it out.

Another way to inspect your mass air flow sensor is by plugging an onboard diagnostics reader (OBD reader) into your car. It’ll be able to read all the errors in your vehicle’s system. The OBD will narrow down any issues with your mass air flow sensor.

Plugging an onboard diagnostics reader or OBD can help you detect issues with your mass air flow sensor.
Click a star to rate this article
[Total: 12   Average: 4.5/5]

Staff Writers

In the Garage with is an online blog dedicated to bringing DIYers and devoted car enthusiasts up to date with topical automotive news and lifestyle content. Our writers live and breathe automotive, taking the guess work out of car repairs with how-to content that helps owners get back on the road and keep driving.

File Under : DIY Tagged With :