Genuine OEM Volkswagen Lambda Probe, part number 04L906262AG. This sensor, also known as an oxygen sensor, measures the amount of oxygen in the exhaust gases. This data is crucial for the engine control unit to adjust the fuel-air mixture for optimal combustion, fuel efficiency, and reduced emissions. It is typically installed in the exhaust manifold or pipe. Genuine OEM lambda probes are precisely calibrated to ensure accurate readings and reliable performance, contributing to a healthy engine and clean exhaust.