Have you started noticing that your driving experience isn’t the same anymore? One fine day, while all set to head to work, my beloved car failed me. The engine wouldn’t start easily and when it finally did, my car got all bumpy and shaky. I had no other choice but to pull it in the garage and take the subway.

I did get it diagnosed finally and the mechanic told me it was the faulty mass air flow sensor. I had been ignoring the seemingly harmless bad mass air flow sensor symptoms for a while that eventually cost me a good deal. I have put together this article because I don’t want you to go through the same troubles I did.

What is Mass Air Flow Sensor Exactly?

Mass Air flow or MAF sensor is an electronic device that sends the statistics to the computer of the engine. The computer uses the data from the sensor to determine the spark timing and fuel delivery. Typically, MAF incorporates an electrically charged cable or wire to calculate the airflow volume into the intake.

The amount of airflow generates corresponding voltage, whose measurements are fed to the computer through the sensor. Based on the reading, spark advance, fuel delivery, and spark timing is adjusted. A faulty MAF sensor eventuates many engine related issues including excessive fuel usage, rough idle, and even stalling of the engine.

Bad Mass Air Flow Sensor Symptoms?

The mixture of the fuel and air to the engine plays an important role in ensuring that the machine operates smoothly. There are various factors and parts that are used to regulate the quantity of fuel and air mixture. MAF apparently plays a very critical role in this. The objective of this sensor is to determine the amount of air entering the system so that it can tell the engine the amount of fuel required for the compensation.

Many years of use causes the damage to the sensor and thus it is not able to measure the amount of airflow accurately. A damaged or defective mass air flow sensor affects the smooth operation of the engine and can also cause many other issues. When unattended for a long time, the defective MAF may render the engine completely inoperable. This is why it is crucial to look out for the bad mass air flow sensor symptoms.

The symptoms

Detect The Bad Mass Air Flow Sensor Symptoms And Spare Yourself Some Serious HasslesCheck Engine Light: Also sometimes referred to as Service Engine Soon Light is one of the earliest indicators of the defective mass air flow sensor. This light is on the instrument panel of the car, usually around the speedometer. The light remains constantly illuminated in case there is a problem in the car engine. However, some of the modern cars may not flash the light until the engine has detected repeated occurrences of the same problem.

The Check Engine Light trigger can be caused by just about any fault in the engine and not necessarily by the defective MAF. This is why it is vital to carefully analyze the computer of the car to pinpoint the exact issue.

The DIY enthusiasts can use the digital diagnostics scanner tool for the car to identify the exact nature of the problem. If it points to the faulty MAF, it must be repaired or replaced. The other option is to turn the car in the garage to allow the auto mechanic to run the diagnostics.

Loss of power: This is again one of the earliest signs that tell you there is possibly a fault with the MAF sensor. When you start feeling that the car is not generating enough power and acceleration isn’t as quick as it was before, get your car checked.

The engine problems: When there is a problem with MAF, your driving experience will not be as smooth as it used to be. In fact, the problems are usually more than subtle and may keep you from driving. Defective MAF leads to improper functioning of the engine causing low compression, low vacuum, fuel pump issues, and reduced fuel pressure. These internal problems manifest as the following most common mass air flow sensor symptoms:

  • The engine doesn’t start easily and causes troubles while turning over
  • The engine becomes shaky upon acceleration
  • The engine becomes jumpy while the vehicle is on the move
  • The engine idling is unusually rich or lean
  • The engine stalls, a little while after starting

Reduced Fuel Efficiency: The problem in the sensor develops gradually and in the beginning the insignificant changes in the mileage may go completely unnoticed. However, once your car starts consuming more fuel than usual, then you may very well attribute the problem to the faulty MAF sensor.

How to Fix the bad MAF sensor?

Here is the three-step process to fix the MAF sensor. But be prudent!

  1. Open the air box of the car using a screwdriver and pull the sensor out. You will want to be very careful here to make sure that no wires are damaged. They may cost you more than $100 in replacement.
  2. Clean the sensor by putting it in the plastic bag full of rubbing alcohol. Shake it a bit to wash out the dirt and grime. That’s an inexpensive option. If you are looking for something more effective, buy a cleaner designed especially for the MAF sensor. It comes in the form of a spray.
  3. Let the sensor dry for about half an hour and then put it back in the air box. Make sure that it is completely dry before reinstallation or you may be looking at some really serious damages.


Reduced fuel efficiency, loss of power, trouble starting the engine, and engine stalling are some of the most telling bad mass air flow sensor symptoms. If you experience any of it, do not waste any time; get your engine checked. Try the DIY steps I have outlined if you know your car well. Else, take it to the mechanic. If you have any questions or suggestions, please feel free to comment below.