Mass air flow sensor (MAF) determines the mass of air entering a vehicle's fuel injection engine, and passes that data to the Engine Control Unit, or ECU. The air mass information is necessary for the ECU to correctly balance and deliver the correct amount of fuel to the engine. When a vehicle's mass airflow sensor is faulty or defective it can cause a variety of problems, and usually results in very poor performance from your engine.
Symptoms of a Faulty Mass Air Flow Sensor
A faulty mass airflow sensor will cause problems similar to low compression or low vacuum, and will also show symptoms similar to when your vehicle has low fuel pressure from a faulty fuel pump. Here are some of the most common symptoms of a faulty mass airflow sensor:
- The engine is very hard to start or turn over
- The engine stalls shortly after starting
- The engine hesitates or drags while under load or idle
- Hesitation and jerking during acceleration
- The engine hiccups
- Excessively rich or lean idling
If you believe your car has a faulty mass air flow sensor, take it to a qualified mechanic so that a complete computer diagnostic can be run. In most cases, a faulty mass flow sensor has a specific code that will generate during computer diagnostics, and is usually easy to determine with computer testing equipment.