The Role of Mass Airflow Sensors and How to Tell If Yours Is Failing

The mass airflow sensor (MAF) is a vital component of a vehicle’s electronic fuel injection system. Located between the air filter and the engine’s intake manifold, the MAF measures how much air is being drawn into your engine. This is important because it allows the engine to maintain the proper balance of air and fuel in the combustion chamber.

Maf Sensor

Signs of a Failing Mass Airflow Sensor

The mass air flow sensor is constantly exposed to moving air, exhaust fumes, fine dust particles that escape the air filter and other debris; over time, it can become contaminated with these particles or fail completely. If the mass airflow sensor is dirty or failing, it makes it difficult for the engine control module (ECM) to correctly calculate the fuel injection. When this happens, it can cause a variety of performance issues with your vehicle.

Here are some of the most common signs you may need your MAF cleaned or replaced:

The Check Engine Light is On

A faulty MAF is one of the most common reasons for the check engine light to come on; it can indicate the sensor isn’t working properly or is completely malfunctioning. Regardless of how your car is running, it’s best to schedule diagnostics any time your check engine light is on to prevent the issue from getting worse—and a more expensive repair.

Jerking and/or Hesitation

Unusual hesitation or sudden, powerful jolts from the engine are often signs of MAF sensor issues; they can happen while you’re accelerating on the freeway or even when traveling at a moderate speed. Either of these issues can be very dangerous, especially in heavy traffic.

Engine Running Too Rich or Too Lean

The powertrain control module (PCM) manages major systems in your car, including the engine and transmission. Without a working MAF sensor, the PCM can’t determine how much fuel the engine needs. This can cause it to run too lean (not enough fuel) or too rich (too much fuel), resulting in an incomplete combustion process.

If your engine is running too rich, you may notice issues like decreased fuel efficiency, rough idling, or black smoke coming from the tailpipe. If the engine is running too lean for too long, you may experience hard starts, engine stalling, and surging.

Keep in mind that the above issues don’t necessarily mean your MAF sensor is faulty. Several problems can mimic a faulty MAF sensor, including a vacuum leak or clogged air filter, restricted catalytic converter, broken intake tube, or restricted exhaust. This is one reason why it’s always best to have the issue properly diagnosed by a qualified auto repair shop.

Preventing Mass Airflow Sensor Failure

Fortunately, there are several steps you can take to keep your MAF sensor in good condition:

  • Replace your engine filters regularly
  • Avoid prolonged idling
  • Avoid sudden acceleration
  • Have inspections performed regularly of the intake system
  • Avoid harsh driving conditions if at all possible, such as sand storms or driving through deep water

For your car to run properly, it needs to have the proper air-to-fuel ratio. If you’ve noticed performance or power issues, or your check engine light is on, schedule an appointment at Accurate Automotive Attention. Established in 1969, we’re Yuma’s only AAA-Approved auto repair shop and have been voted Yuma’s Best Auto Repair 20 years in a row. Our skilled technicians will quickly determine the root of the issue and have your vehicle back on the road in no time. Contact us today or request an appointment online.