Mercedes-Benz provides drivers all over the world with flawless design and engineering, but just as with any car they see component failures. One common issue we see is mass air flow sensor failure. A mass air flow sensor is often referred to as a MAF sensor. Its function is to measure air density in the engine. The data that it collects helps maintain the proper air-fuel ratio.

When functioning correctly, the MAF sensor helps with your fuel economy, engine operation, and engine power. When your mass air flow sensor fails, it can cause your Mercedes to idle roughly or stall. You will also experience reduced gas mileage.

Function of a Mass Air Flow Sensor

The mass air flow sensor detects the volume of air entering the engine. This data is transmitted to the car’s computer. The computer then determines if more or less fuel is needed.

Symptoms of a Defective Mass Air Flow Sensor

The mass air flow sensor can easily be damaged or soiled. If the air filter is old or improperly installed, it can let dirty air into the engine.  If the air filter is oil soaked, it can contaminate the engine. A bad mass air flow sensor cannot measure air flow properly. It will provide incorrect readings and act erratically. These improper readings can lead to several common problems.

Common symptoms of a Defective Mass Air Flow Sensor

Reduced Fuel Economy

A faulty mass air flow sensor can drastically reduce your fuel economy. You will often notice you are making frequent stops at the gas station. This will lead to a waste of money as well as time. Keeping track of your fuel economy will help you catch problems.

Lack of Power

If your vehicle was once powerful but now doesn’t have the reaction that it once did, it might be due to your MAF sensor. This is because the engine isn’t able to produce enough power.


Your car may start fine, but after a few minutes, it stalls. This usually happens when the mass air flow sensor is just beginning to fail. When the sensor begins to measure the air flow, it gets the correct information, but soon after, it will start getting erratic readings.

Issues Starting Your Mercedes

A defective mass air flow sensor can make starting your car difficult. It should start as soon as you turn the key. Since the sensor isn’t gathering the proper information, your spark plugs may not be receiving the adequate air-to-gas mixture.


You may notice a hesitation when you give the car more gas. When working correctly, your car should accelerate right away. A bad mass air flow sensor can restrict your engine from getting a steady flow of gasoline. Hesitancy can be dangerous and can lead to accidents.

Jerking or Hiccupping During Acceleration

A failing mass air flow sensor can act erratically. This can lead to jerking or hiccupping during acceleration.

Rich or Lean Idling

If the mass air flow sensor will not allow your engine to get the proper amount of fuel. If it isn’t getting enough, it is referred to as lean idling. If it is getting too much, this is referred to as rich idling.

Black Exhaust Smoke

When your engine is receiving too much gas, you may have black smoke coming out of your exhaust. The unburned fuel mixes with water vapor and carbon dioxide. This mixture produces smoke that is released out of the exhaust.

European Motor Cars Will Help You

At European Motor Cars, our technicians Mercedes Mass Airflow Sensor Checkare factory-trained and Master Status Certified. We have over 30 years of experience servicing European vehicles. You don’t have to take your Mercedes to a dealership, as our technicians can fix any issue that you have quicker and cheaper.

If you need to have your mass air flow sensor replaced or need any other service, schedule an appointment today. You can reach the European Motor Cars office at (702) 367-7140. You can also stop by and see us at 3440 Spring Mountain Road in Las Vegas, NV. We are conveniently located near Spring Valley, Summerlin, Henderson, North Las Vegas, and Las Vegas, NV. We look forward to serving you today.

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