Oxygen Sensor

The Bosch Mass Air Flow (MAF) Sensor is a crucial "hot film" type component that precisely measures the volume of air entering your engine's intake system. This information is vital for the Engine Control Module (ECM) to accurately calculate fuel injection, ignition timing, and other critical parameters, ensuring optimal performance, fuel economy, and emissions control. Over time, MAF sensors can degrade or fail due to age and continuous operation. Symptoms of a faulty sensor include a illuminated "Check Engine" light (often with MAF-related diagnostic trouble codes), rough idling, engine stalling, incorrect fuel trim readings (rich at idle or lean under load), or the engine constantly running too rich or too lean. In some cases, a failing MAF sensor can even trigger a limp mode, restricting engine power. Bosch, a globally recognized leader in automotive electronics and sensors, manufactures this OE-quality replacement part in Germany. Their extensive experience, dating back to the invention of mass production fuel injection and lambda sensors, ensures reliable and precise measurements. This specific Bosch MAF sensor, part number 0280217121, is designed as a direct fit replacement for various Volkswagen, Audi, SEAT, and Skoda models, primarily those equipped with the 1.9L ALH TDI diesel engine. Its OE number equivalents include 038906461C, 0281002757, and 63137. Proper functioning of the MAF sensor is essential for efficient combustion and maintaining peak engine performance.