When a massive airflow, or MAF, sensor is defective, the right amount of air does not enter the engine. This leads to poor overall performance of the vehicle.
The MAF measures the air entering a vehicle's intake, which is part of the fuel injection engine. The MAF sensor communicates the airflow measurements to the vehicle's engine control unit, or ECU. The ECU is the vehicle's onboard computer, which takes the airflow information and calculates the delivery of fuel and the timing of the spark.
If the MAF sensor is not functioning properly, it creates a number of problems that affect the performance of the vehicle, which mainly manifest in the engine. The engine can be difficult to start, or hesitate, stall, hiccup or drag after starting. There can also be jerks or hesitation while the vehicle is accelerating.
A defective MAF sensor typically generates a particular code that a mechanic can determine easily using computer diagnostic tools. As replacing a faulty MAF sensor can be costly, drivers can take preventative measures by maintaining the sensor around twice per year or when they change the oil or air filter. This involves removing, cleaning, drying and then reinstalling the MAF sensor.