McCullough NAPA Auto Care

7 Symptoms of a Faulty Mass Air Flow Sensor

The mass air flow sensor in your car measures the air mass that flows into your engine intake. Many modern electronic engine controls calculate the correct quantity of fuel for any given situation, and your MAF sensor works with your fuel injectors to make this happen. Measuring air mass in your engine is crucial for calculating how much fuel to add when achieving the correct air-fuel ratio. If your vehicle is experiencing performance issues, it may be due to one of these symptoms of a bad mass air flow sensor.

7 Symptoms of a Faulty Mass Air Flow Sensor

Not all the symptoms of a bad mass air flow sensor are obvious. We’ve outlined some of the notorious issues below. 

1 – Trouble Accelerating

Do you experience problems accelerating while passing or driving down the highway? This could result from your engine control module limiting fuel injection because of problems with your mass air flow sensor.

2 – Poor Fuel Economy

Since the mass air flow sensor measures how much air mass is in your engine, having a faulty MAF sensor can result in more fuel being injected than necessary. This can reduce your overall fuel economy. 

3 – Check Engine Light Is On

Some modern vehicles may show the check engine light when there are issues with your mass air flow sensor. Fuel trim and misfire codes can also be linked to the MAF sensor. 

4 – Rough Idle

Achieving a smooth idle is challenging without the proper amount of fuel being injected into your engine. A faulty MAF sensor may cause your engine to chug due to misreading the air mass and desired fuel levels. 

5 – Surging or Hesitation

You may notice that your car hesitates to accelerate or releases an abnormal burst of power. This is likely due to your MAF sensor misreading the amount of air mass in your engine and your fuel injectors depositing the incorrect amount of fuel as a result.

6 – Hard Starting

More fuel is required to start an engine than to keep it idle. If your MAF sensor is bad, your engine control module may not send enough fuel into your engine to turn it over.

7 – Black Smoke Out of the Exhaust

If your engine control module sends too much fuel into your engine, black smoke may come out of the exhaust. Your engine control module would likely do this because your MAF sensor gave an incorrect reading. This may also cause your catalytic converter to overload. 

Schedule Your Appointment with McCullough NAPA Auto Care

It’s important to note that these issues don’t always mean that your mass air flow sensor is faulty. Issues such as a clogged air filter, vacuum leak, restricted exhaust, clogged catalytic converter, or a broken intake tube can mimic the functions of a bad MAF sensor. If you are experiencing any of these signs above, we urge you to bring your car to McCullough NAPA Auto Care for an honest inspection of your MAF sensor and intake system. We will check all the sensors available and run a diagnostic test to pinpoint exactly what may be causing these issues. From there, we’ll recommend the necessary service and make the repairs for you in a timely, professional manner.