What Happens When the Mass Airflow Sensor Gets Dirty?

In our last blog post, we talked about a malfunctioning oxygen sensor. Let’s talk about the mass airflow or MAF sensor in this post. This sensor is located in your vehicle’s engine; you’ll find it behind the air filter. It tracks how much air flows through the grille and into the engine from the outside. Hummel’s Automotive Diagnostic & Repair explains that you may never have to replace the MAF sensor but it can get dirty. When it does, the following problems occur.

Acceleration Lag

Oftentimes, when the mass airflow sensor is dirty, it confuses your vehicle’s main computer chip. This chip, which is called the engine control unit or ECU, controls the amounts of air and fuel in the combustion chamber. If it puts too much air in the chamber, your acceleration will lag.

Black Exhaust

The opposite is too much fuel in the chamber and this can cause black exhaust to flow out of your tailpipe. What is causing the black exhaust is a fuel burn going on inside your engine. The engine can’t return the excess fuel to the tank so it burns it instead.

Check Engine Warning

A dirty MAF sensor will also confuse the ECU, and it will turn on the check engine light on your dashboard to let you know something’s off in the engine. In this case, what is off is the MAF sensor. Cleaning the sensor usually solves the problem.

Engine Performance Problems

We talked about acceleration lag above, and the same condition in the combustion chamber can also make your engine lag, especially when you are driving at higher speeds. Your engine will surge forward like a bucking bronco if there is too much fuel in the chamber.

Hard/No Starts

The worse thing that can happen if your mass airflow sensor is dirty is your car, truck, or utility vehicle won’t start at all. It might be difficult to start a few times before it refuses to start, so it’s best to have the problem looked into sooner rather than later.

Poor Fuel Economy

The MAF sensor can also wreak havoc with your vehicle’s fuel economy. For example, if the engine is burning through excess fuel, you will go through a full tank quicker. This being said, a fuel-starved engine can also reduce your fuel economy.

Rough Idling

Finally, any imbalance between the air and fuel will make your vehicle idle roughly. This can leave you stressed because you aren’t sure if your vehicle is going to stall while you are stopped.

Hummel’s Automotive Diagnostic & Repair in St. George, UT, is all you need to resolve the problems listed above. We can clean your MAF sensor and restore your engine’s performance.

Photo by Mariia Demchenko from Getty Images via Canva Pro

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