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7 Signs of Mass Air Flow Sensor Failure

When the mass air flow (MAF) sensor on a car begins to fail, it can cause several drivability issues. Let's discuss what an MAF sensor is and why it is important. We'll also look at seven signs that point to potential failure.

mass air flow sensor in engine

What is a Mass Air Flow Sensor and Why is It Important?

In modern fuel-injected engines, the MAF sensor measures the mass of air entering the engine. Located between the air filter and the intake manifold, it helps to ensure that the proper air-fuel ratio is maintained to keep the engine running smoothly. The amount of oxygen in the air, which affects combustion, varies with temperature and pressure. The MAF sensor takes air density into account to provide a more accurate reading.

Signs of Mass Air Flow Sensor Failure

MAF sensor failure can cause the engine computer to miscalculate the amount of injected fuel. When this happens, the engine can malfunction.       

Here are seven signs that the MAF sensor may need some attention.

  1. Check Engine Light: A failed MAF sensor may trigger the check engine light to come on.
  2. Stalling: A failing MAF can cause the engine to stall by sending incorrect readings to the engine computer.
  3. Black Exhaust Smoke: Black exhaust smoke is a sign that there is too much fuel in the air/fuel mixture.
  4. Rough Idle: A rough idle occurs when engine RPMs fluctuate up and down. This can happen when a failing MAF sends incorrect readings to the engine computer.  
  5. Slow Acceleration: Inaccurate air intake readings can cause the car to feel sluggish when the driver tries to accelerate. 
  6. Difficulty Starting: If the engine computer is not receiving accurate readings on the amount of air entering the engine, it may not be able to provide enough fuel to start the engine.
  7. Unusual Engine Noises: Pinging or knocking is a sign of the engine running lean or rich. This could be a sign of a failing MAF sensor.

A failing MAF sensor can cause serious damage to your car's engine. Have your care inspected by a trusted mechanic if you experience any of these symptoms. 

Engine and Fuel Injection System Repair from Custom Complete Automotive

Custom Complete Automotive has been providing unmatched repairs and unparalleled service for over 40 years. If you suspect a problem with your car's mass air flow sensor, contact us today! 

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About the Author
Eric Riddles

Eric Riddles is an ASE Certified Master Automobile Technician who has been working as an auto mechanic since 1998 and originally joined the team at Custom Complete Automotive in 2005. Eric has numerous certifications in various aspects of car repair and spent 10 years training the next generation of auto technicians at a local high school Auto Shop classroom.

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