FITMENT
Compatible with Volkswagen Group diesel vehicles equipped with SCR (Selective Catalytic Reduction) AdBlue emission systems requiring NOx monitoring.
Common applications include:

• Audi A6 (2.0 TDI / 3.0 TDI SCR variants depending on engine code)
• Audi A7 Sportback (diesel SCR variants)
• VW Touareg (MQB/MLB diesel SCR variants depending on model year)
• VW Passat B8 (2.0 TDI SCR Euro 6 variants)
• VW Tiguan / Arteon (select SCR diesel configurations)
• Seat / Skoda MQB platform 2.0 TDI SCR systems
• Euro 6 diesel SCR aftertreatment systems

OEM / CROSS REFERENCES

• 04L907807S (OEM VAG part number)
• 5WK97312 (Continental/VDO sensor cross-reference)
• SNS312 / SNS705 series (platform-dependent designation)
• 04L907805S / 04L907807AC (related revision variants in same sensor family)

FUNCTION
This NOx sensor is part of the SCR exhaust aftertreatment system. It measures nitrogen oxide (NOx) levels in exhaust gases and sends data to the ECU to control AdBlue (DEF) injection, ensuring emissions compliance and optimal catalyst efficiency under Euro 5 / Euro 6 standards.

FAQ
Q1: What does this NOx sensor do?
It measures NOx emissions in the exhaust and helps regulate AdBlue dosing in the SCR system to reduce harmful gases.

Q2: Where is it installed?
In the SCR exhaust system, typically mounted before or after the catalytic converter depending on vehicle configuration.

Q3: What are symptoms of failure?

• Check engine light
• SCR / AdBlue warning messages
• NOx sensor fault codes (P2200–P229F common)
• Reduced engine power or limp mode

Q4: Are 04L907807S and 5WK97312 interchangeable?
Yes, 04L907807S is the OEM VW/Audi reference and 5WK97312 is the supplier cross-reference for the same NOx sensor unit, but correct fitment depends on ECU calibration and engine code.