This air flow sensor measures the mass or volume of intake air entering the engine. It sends a voltage or frequency signal to the engine control unit, which uses the data to calculate the correct fuel injection quantity and ignition timing. The sensor is positioned in the intake duct between the air filter and the throttle body or turbocharger inlet. A contaminated or failed sensor produces an incorrect signal, leading to poor fuel economy, reduced power, or black smoke. This component matches the original sensor’s calibration curve and connector geometry, so no wiring modification or signal offset is required for the engine management system to read correctly.