A mass air flow sensor, or MAF, is a tool found in modern engines used to monitor the incoming air. This information is essential for the engine control unit (ECU) to deliver a balanced amount of fuel mass to the engine. It is usually installed inside the intake air duct between the air filter and the engine.
Typically a MAF is used in conjunction with an oxygen sensor to control the engine’s air-to-fuel ration very accurately. The MAF will provide the “open-loop” predicted air flow information to the ECU, while the oxygen sensor provides the “closed-loop” feedback in order to make minor corrections to the predicted air mass.
