Genuine OEM Nissan Mass Air Flow Sensor, part number 294G09PB0A. This sensor accurately measures the volume and density of air entering the engine's intake system, providing critical data to the engine control unit (ECU) for precise fuel injection and ignition timing. It is typically installed in the air intake duct between the air filter and the throttle body. Accurate air flow measurement is essential for maintaining optimal engine performance, fuel efficiency, and emissions control. Genuine OEM sensors are calibrated to precise specifications, ensuring reliable and accurate readings for consistent engine operation.