Signs I Need to Replace My Car’s MAF Sensor

If you take excellent care of your automobile, your mass airflow (MAF) sensor may never need to be changed. There will come a point when it needs to be cleaned, however. Techway Automotive explains that the signs of a MAF sensor going bad can also be the symptoms of a dirty MAF sensor. Let’s talk about the signs below so you know what to look for.

Acceleration Problems

If the mass airflow sensor is malfunctioning, it will send incorrect air intake readings to the engine control module. Currently, the module may think that the engine needs more air in the combustion chamber when it doesn’t. This will cause a lean fuel mixture in the chamber and your vehicle’s acceleration will become sluggish and lag.

Black Engine Exhaust

The incorrect readings might also cause the MAF sensor to trick the module into putting too much fuel in the combustion chamber, and this rich fuel mixture might create black exhaust. If you see black exhaust flowing out of your tailpipe, your engine is burning fuel. This can be caused by a faulty MAF sensor.

Check Engine Warning

When the mass airflow sensor goes bad, it will send an error code to the engine control module. To alert you that there’s a problem, the module will turn on the check engine light. Running a diagnostic check to determine why the check engine light is on will point to the MAF sensor’s error code.

Hard Starting

You may also find it difficult to get your vehicle started. This could be because you have a lean fuel mixture and your engine is fuel-starved, or it could be that you have a rich fuel mixture and the engine is flooded with fuel. A dirty MAF sensor can cause either fuel condition.


When there is a lean fuel mixture in the combustion chamber, your acceleration will hesitate as discussed above but your engine may also hesitate. Once you get your vehicle up to speed, your engine may stutter and struggle.

When there is a rich fuel mixture, your car may turn into a bucking bronco. As the engine burns away the excess fuel, your vehicle will pick up speed (surge) even though you haven’t changed your foot pressure on the accelerator.

Poor Gas Mileage

Another sign of a malfunctioning MAF sensor is poor gas mileage. If the engine is burning away excess fuel, your gas mileage will suffer. You may not notice this at first. The reduction in fuel economy may be subtle.

Techway Automotive in Dothan, AL, or Blakely, GA, can help. We can run a diagnostic check to see why your engine is having performance issues. If it is the mass airflow sensor, we can clean or replace it.

Written by Developer Autoshop