The answer to the titled question is both. The mass airflow (MAF) sensor can malfunction when it gets dirty or just malfunction. We advise that it is rare to have a problem with your vehicle’s MAF sensor. This being said, we are going to list the signs of a faulty MAF sensor below so you know what to look for in your car, truck, or utility vehicle.
Check Engine Warning
A malfunctioning MAF sensor can trigger a check engine light warning because it indirectly throws off the balance of air and fuel in the combustion chamber. The MAF sensor tracks the incoming air that is used in the combustion chamber. If it goes bad, the main computer chip may receive false air inflow data. Consequently, it will make unnecessary adjustments in the combustion chamber that will affect system sensors. When these sensors report an error, the chip will turn on the check engine light.
One of these adjustments is to add unnecessary air into the combustion chamber. When this happens, your vehicle’s acceleration will lag because the engine is being fuel-starved. In other words, there is too much air and not enough fuel in the combustion chamber to sustain smooth acceleration.
You will also end up with a sputtering engine if the combustion chamber is filled with air. The opposite can occur, as well. The main computer chip may think – incorrectly – that the combustion chamber needs more fuel when it doesn’t. This causes your engine to pick up speed in unexpected spurts.
Rough Engine Idle
Getting back to a lean fuel mixture, the excess air can also affect how smoothly your engine idles. In the case of fuel starvation, the engine idle will be rough and your engine may even stall. This can all be caused by a dirty MAF sensor that needs to be cleaned so it stops malfunctioning.
Reduced Fuel Economy
Anytime your engine struggles to run, it will burn through more fuel. When this happens, you will see a noticeable reduction in your vehicle’s fuel economy. This can be frustrating, especially with what gasoline and diesel fuel cost these days. Replacing the faulty MAF sensor can solve the problem.
Black Exhaust Smoke
Finally, if there is too much fuel in the combustion chamber, you may end up with black exhaust flowing out of the tailpipe. This can be alarming, especially if there are also sparks or flames mixed in with the exhaust. This is rare, but it can happen if the fuel mixture is extremely rich.
We can test your MAF sensor to see if it is causing the problems listed above. If it is, we will replace it.