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

• Audi A6 C8 (2018–2022 2.0 TDI / 3.0 TDI SCR variants)
• Audi A7 Sportback (2018–2022 diesel SCR variants)
• Audi A6 Allroad (C8 platform SCR diesel variants)
• Audi S6 / S7 TDI (diesel SCR variants depending on engine code)
• Volkswagen Group MLB Evo diesel platforms

Using reference numbers:

• 4K0907807A
• 4K0907807D
• 4K0907807F
• 4K0907807E
• SNS705C / SNS705 series
• 5WK97434 / related Continental/VDO SCR NOx sensor equivalents

This sensor is part of the SCR exhaust aftertreatment system and monitors nitrogen oxide (NOx) levels to regulate AdBlue dosing for Euro 6 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 data to the ECU to control AdBlue injection and reduce emissions.

Q2: Where is it installed?
A2: It is installed in the SCR exhaust system, typically before or after 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: Are 4K0907807A / D / E / F interchangeable?
A4: They are revision variants within the same Audi A6/A7 SCR sensor family. However, compatibility depends on engine code, ECU software, and exact emissions configuration.