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

• Audi Q5 (FY / 80A platform diesel SCR variants 2.0 TDI / 3.0 TDI depending on engine code)
• Audi SQ5 (diesel SCR variants depending on model year)
• Related Audi Q5 platform vehicles using MQB / MLB Evo SCR systems
• Euro 6 diesel SCR aftertreatment systems

Using reference numbers:

• 80A907807L (OEM Audi/VW part number)
• SNS731A (Continental/VDO sensor family cross-reference)
• 5WK97438 (manufacturer sensor equivalent reference)

This NOx sensor is part of the SCR exhaust aftertreatment system, used to measure nitrogen oxide (NOx) levels and control AdBlue/DEF injection for emissions compliance.

FAQ
Q1: What is the function of this NOx sensor?
A1: It measures nitrogen oxide (NOx) levels in the exhaust system and sends real-time data to the ECU to regulate AdBlue injection and reduce emissions.

Q2: Where is it installed?
A2: It is installed in the SCR exhaust system, typically upstream or downstream of the catalytic converter depending on vehicle configuration.

Q3: What are symptoms of failure?
A3: Check engine light, SCR/AdBlue warnings, NOx sensor fault codes, reduced engine power, or limp mode activation.

Q4: Is 80A907807L interchangeable with SNS731A?
A4: Yes, 80A907807L is the OEM Audi/VW reference and SNS731A / 5WK97438 are supplier cross-references for the same NOx sensor unit, but final fitment depends on engine code and ECU calibration.