Mass Air Flow Sensor Symptoms (And How to Clean It)

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David Lawrence

Mass Air Flow Sensor Symptoms

A mass air flow [MAF]  sensor is critical to good vehicle health. Sometimes, it degrades over time due to a variety of reasons. If you are also experiencing such bad mass airflow sensor symptoms, we are here to help you get a clean mass air flow sensor in no time. 

A clean mass air flow sensor will give you a healthy car with proper fuel usage. A degraded air flow sensor, on the other hand, will not only sabotage your car but also increase your expense if you ignore it for a long time. This is why it is critical to know some common bad MAF sensor symptoms to stay ahead in the long run. 

In this article, we will highlight the importance of a MAS and explain the symptoms of a bad MAF so that if you catch any of these in your car, you can take it to the service center or get it repaired as soon as possible. Alternatively, we are going to explain how to clean the sensor yourself if you do not want to take it to the service center. 

What is a Mass Air Flow Sensor?

The mass air flow sensor calculates how much air is pulled into the engine during regular operation. This air mass measurement is crucial for determining the necessary fuel to achieve the optimal air-to-fuel ratio (AFR).

The Electronic Control Unit (ECU) requires air mass information to accurately balance the engine and supply the right quantity of fuel. When a vehicle’s mass airflow sensor is damaged or not functioning correctly, it can result in various issues, one of which is often a decline in the engine’s overall performance.

This decline can cause additional problems for the vehicle, such as poor acceleration and incorrect fuel delivery. As a result, maintaining the MAF sensor’s good condition is vital for ensuring the vehicle’s overall performance.

Bad Mass Air Flow Sensor Symptoms 

  • The Check Engine Warning Light is on
  • Trouble with Acceleration
  • Smooth Idle 
  • Dark Smoke From the exhaust 
  • Lagging 
  •  Bad Fuel Efficiency 
  • Difficulty in Starting the Car or Engine

Now that you know everything about the functioning of a mass airflow sensor, we are going to dwell upon some common symptoms of a bad mass air flow sensor. If you see any of these in your vehicle, it might be time to get it checked or cleaned. 

These symptoms might also be occurring due to other reasons. Therefore it is best to get the car checked before you move on to clean the sensor on your own. Let’s check out the most common symptoms.

The Check Engine Warning Light is on

A warning light on the dashboard called the check engine light, may illuminate if there is an issue with the MAF sensor. This can occur due to error codes produced by circuit diagnostics. Nonetheless, the mass air flow sensor damage can also result from misfire codes and improper fuel trim adjustments.

If the onboard diagnostics (OBD) scanner displays the code P0101—Mass Air Flow Sensor Circuit Range/Performance, the MAF sensor may be obstructed and may be one of the bad MAF sensor symptoms. If your car displays the said code, it is almost always correct. 

Trouble with Acceleration

When the MAF sensor is dirty, acceleration can be affected, becoming particularly evident as the vehicle prepares to enter a highway. This issue could stem from the MAF sensor or the engine control module limiting the fuel injection, resulting in poor acceleration.

While other factors might contribute to sluggish acceleration, the MAF sensor plays a considerable role in influencing a car’s acceleration and should not be overlooked.

Smooth Idle 

Attaining a smooth engine idle can be difficult without the correct amount of fuel, as an appropriate fuel level is needed for a smooth idle. If the MAF sensor is malfunctioning, the engine may not run smoothly, especially during idling.

As a result, rough idling can be one of the indicators of a defective MAF sensor, directly caused by an insufficient fuel supply to the engine. If you notice such roughness while idling, it might be time to clean the MAF sensor.

Dark Smoke From the Exhaust 

If the engine control module (ECM) is malfunctioning, the vehicle’s exhaust system may occasionally produce black smoke. The catalytic converter sometimes overloads itself due to a bad MAF sensor.

Therefore, it is necessary that you may get it checked if you are experiencing an unreasonably high amount of dark fumes coming out of the exhaust. 


Unusual power surges or a lack of power while cruising or accelerating are among the most prominent symptoms that can be seen when an engine’s mass air flow sensors are not functioning correctly.

 Bad Fuel Efficiency 

A faulty ECM could lead to an increased amount of fuel being added, resulting in increased fuel consumption. As a direct result of this, one of the symptoms of a faulty MAF sensor is a reduction in the vehicle’s fuel economy.

To experience this, you might notice it unintentionally, or you might have to keep a tab on the fuel consumption of your car and its mileage.

Difficulty in Starting the Car or Engine

One possible symptom of a faulty MAF sensor is the inability to start the vehicle. It takes more fuel to get an engine up and running than to let it idle. 

Sometimes, the car starts briefly and then stops running altogether, which is also a cause for concern. Therefore, a lack of adequate fuel may either lag your car or stop it from running. 

How to Have a Clean Mass Air Flow Sensor?

Once you have identified these bad mass airflow sensor symptoms, the next logical step is to get it cleaned. It would be best if you cleaned your mass airflow sensor every six months or whenever you change the oil in your vehicle, whichever comes first. 

Here are some of the basic steps you need to take to clean a bad MAF sensor on your own. It is easy to do and can be done by anyone with the right amount of precision and time. 

Step 1 – Remove the Sensor 

First, you must remove your mass airflow sensor before you can clean it. This can be accomplished by opening the vehicle’s air box and removing the filter using a screwdriver with a flathead tip. 

When removing the sensor, you must take extreme care not to touch the wires. Although a disconnected mass airflow sensor can’t cause electrocution, the wires are tiny and fragile. 

While removing the sensor, ensure you do not damage any of these wires, or it may result in a costly mistake! 

Step 2 -Scrub the Sensor Clean.

Once the sensor is removed, you have two distinct options. The more cost-effective choice is to place your mass airflow sensor in a plastic bag filled with rubbing alcohol. Agitate the bag within the container to ensure the alcohol cleans the sensor thoroughly, removing all dirt and grime.

Alternatively, you can visit a local auto parts store and buy a cleaner specifically designed for mass airflow sensors, then apply it to the sensor in question.

Step 3 – Replace the Sensor After It Has Been Cleaned.

After cleaning the mass airflow sensor with disinfectant or rubbing alcohol, allow it to sit for at least twenty minutes. Attempting to reinstall the sensor in your vehicle before it completely dries may result in damage.

To avoid damaging the sensor, consider replacing it entirely rather than cleaning it.

This option might be more costly, but it is ultimately safer. Replacing the sensor is a wise choice, even if you’re short on time.


Below are the frequently asked questions on how to clean the MAF sensor and bad MAF sensor symptoms. Let’s dig deep to know more.

Can you drive with a bad mass air flow sensor?

You can drive with a defective mass air flow sensor. However, a faulty mass air flow sensor can cause severe engine hiccups, so driving is valid, but only for a short period of time before things go haywire. As established earlier in the article, a sub-par mass air flow sensor can cause severe car problems.

How much does it cost to fix a mass airflow sensor?

Replacing the mass airflow sensor should cost $350 or less for parts and labor charges for most cars, trucks, and SUVs running on the road.

Is it true that my MAF sensor car runs better when I unplug?

Generally, unplugging your MAF sensor will make your car run worse. However, in some cases, when the MAF sensor is dirty or defective, your engine will run faster and generally perform better with it unplugged. Luckily the MAF sensor is easy to clean and replace.

Can you clean the MAF sensor without removing it?

Removing the MAF sensor from the vehicles is often not compulsory to clean it. That can save you a lot of time and effort. When possible, avoid removing and dismantling components to avoid exacerbating the situation.


We have discussed mass air flow sensor symptoms and how they can damage your vehicle in no time. At this point, it must be clear that cleaning this sensor is very important for the health of your car. Often people don’t recognize the symptoms that the car is showing, which would lead to cleaning or replacement. However, if you have carefully read the above points, you must be able to figure it out easily when a car is not in good condition. 

We hope we were able to help you identify the problem and solve it as well. All you need to do is pay attention to the changes that you might experience in your car. 

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David Lawrence

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