FITMENT:
Compatible with Mercedes-Benz diesel vehicles equipped with SCR (AdBlue/DEF) Euro 6 systems, including:

• S-Class W222 / V222 / X222
• G-Class W463 (diesel BlueTEC models)
• May also fit GLS / GL / GLE SCR configurations depending on engine variant

OEM / Cross reference numbers:

• A0009057408
• 0009057408
• A0009053309 / A0009058311 (interchange family references)

This is a downstream (post-catalyst) NOx sensor used in Mercedes SCR exhaust aftertreatment systems to monitor catalyst efficiency and emissions performance.

FUNCTION:

• Measures NOx emissions after SCR catalyst
• Sends real-time data to ECU via CAN communication
• Monitors SCR catalyst efficiency and AdBlue performance
• Helps ensure Euro 6 emissions compliance and prevent engine derate

INSTALLATION POSITION:

• Downstream / outlet NOx sensor (rear sensor)
• Mounted after SCR catalytic converter in exhaust system

IMPORTANT NOTE:
A0009057408 is specifically designed for post-catalyst monitoring, meaning it works together with upstream NOx sensor to calculate SCR efficiency. Wrong placement can trigger fault codes.

FAQ:

Q1: Is this inlet or outlet sensor?
A1: This is a downstream (outlet) NOx sensor, installed after the SCR catalyst.

Q2: What vehicles does it fit?
A2: Mercedes S-Class W222, G-Class W463, X222 and related BlueTEC diesel models.

Q3: What are failure symptoms?
A3: SCR warning light, engine limp mode, AdBlue system faults, or NOx efficiency codes.

Q4: Is it plug-and-play?
A4: Yes, but some Mercedes models require SCR reset or ECU adaptation after replacement.

Q5: Is aftermarket safe?
A5: Many aftermarket versions exist, but Mercedes NOx sensors are sensitive—OEM or high-quality Continental equivalents are recommended. (Community reports highlight reliability differences.)