Bosch Mass Air Flow Sensor - 0280218034; Bosch Mass Air Flow Sensors are designed to measure the volume and density of air entering a vehicle's engine. They are a key component in the engine management system, as they help to ensure the air/fuel ratio remains at the correct level for optimum performance and fuel economy. The 0280218034 model is designed to fit a wide range of vehicles and is an ideal choice for those looking for a reliable and accurate mass air flow sensor.