Computers control a major percentage of vehicle engine functions. One important function is how much fuel is delivered to the engine. The computer calculates the amount of fuel needed and when to inject. An important part of the calculation is the proper air and fuel mixture, which is based on volume, temperature, and air density.
The Mass Air Flow (MAF) sensor measures the variables to inform the computer and make adjustments to keep your engine performing efficiently. Outside air enters the air intake system, passes through the engine air filter, flows through the Mass Air Flow sensor, and into the engine.
When your air filter becomes dirty, dust and other contaminants can get through and smother the Mass Air Flow sensor. A dirty sensor can affect the measurement accuracy and report false instructions, which can affect drivability, your catalytic converter, exhaust emissions, trigger a check engine light, and could even prevent your engine from running.
The engine air filter is the first line of defense against such expensive problems. A contaminated Mass Air Flow sensor may be cleaned during an air induction service. If the sensor is damaged, the sensor needs to be replaced.