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

• Audi Q2 (diesel SCR variants 2.0 TDI)
• Audi A3 / A1 (select 2.0 TDI SCR models depending on platform)
• VW Golf / Tiguan / Passat (MQB platform diesel SCR variants)
• Seat Leon / Ateca / Ibiza (SCR diesel variants depending on engine code)
• Skoda Octavia / Kodiaq / Superb (SCR diesel variants)
• Euro 6 diesel SCR systems using MQB platform engines

Using reference numbers:

• 04L907805CF (OEM VAG part number)
• SNS0751C (sensor family / aftermarket cross-reference code)
• Common 5WK9-series SCR NOx sensor platform (depending on supplier version)

This sensor is part of the exhaust aftertreatment system, measuring NOx emissions to control AdBlue injection and ensure Euro 6 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 regulate AdBlue/DEF dosing 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: Is 04L907805CF interchangeable with SNS0751C?
A4: Yes, 04L907805CF is the OEM VAG reference and SNS0751C is the supplier/aftermarket cross-reference for the same NOx sensor unit, but final compatibility depends on engine code and ECU calibration.