Fitment

Confirmed OE application based on OEM cross-reference data:

• Audi A4 (B9 / 8W chassis) 2.0 TDI
• Audi A5 (F5 platform) 2.0 TDI
• Audi Q5 (FY platform) 2.0 TDI
• Volkswagen Group diesel SCR (AdBlue) emission systems using 8W-series architecture

Fitment is strictly based on OE number matching: 8W0907807K

Technical Description

This NOx sensor is used in diesel exhaust aftertreatment systems to measure nitrogen oxide (NOx) concentration in exhaust gases.

It sends real-time data to the engine control unit (ECU) to regulate SCR (Selective Catalytic Reduction) dosing strategy and ensure emissions compliance in diesel vehicles equipped with AdBlue systems.

The sensor is part of the emissions monitoring system used in modern VAG diesel platforms.

Symptoms / Fault Codes

Common symptoms of failure may include:

• Check engine light
• P2200 / P229F fault codes (system dependent)
• SCR / AdBlue system warning
• Reduced engine performance (limp mode)
• Increased emissions

OE / Part Numbers

• 8W0907807K
• 8K0907807K / 8K0907807N (interchange family depending on revision)

FAQ

What does this NOx sensor do?

It measures nitrogen oxide levels in diesel exhaust gases and sends data to the ECU for SCR emission control.

Is this sensor vehicle-specific?

Yes. It is strictly matched by OE number. Even small suffix differences may indicate different calibration or hardware revision.

Can similar NOx sensors be used instead?

Not recommended. NOx sensors are ECU-calibrated components and must match the exact OE specification.

What system is it used in?

It is used in Volkswagen Group diesel SCR (AdBlue) emission systems on B9 / MLB Evo generation vehicles.