Volkswagen Model NOx Sensor 04L907807AJ 5WK97435 Precise Replacement

When your vehicle’s check engine light is on, acceleration is weak, fuel consumption is abnormal, or NOx emissions are high on a tailpipe test, this usually indicates the NOx sensor has aged or failed and cannot accurately monitor NOx concentration in the exhaust. This sensor, in normal operation, provides real-time feedback to the ECU on exhaust composition to help precisely control urea injection in the SCR system, reducing emissions and optimizing engine performance. OEM number 04L907807AJ (corresponding to 5WK97435, SNS436A). Fits many Volkswagen models with 2.0TDI engines, such as Passat, Magotan, Touareg, etc. Installation must be performed with the engine cold to avoid scalding; pay attention to sensor wiring routing to prevent interference with the exhaust or underbody components; after installation, diagnose with a scanner to clear fault codes and reset.