FITMENT:
Compatible with Mercedes-Benz diesel vehicles equipped with SCR emission systems (BlueTEC), including:

• W205 / S205 (C-Class diesel models)
• W166 (GLE / ML)
• W221 (S-Class diesel models)
• X164 / X166 (GL / GLS)
• C207 / A207 (E-Class coupe & cabrio diesel variants)
• W164 / W251 (selected Bluetec configurations)

OEM reference number: A0009051512 (also 0009051512).
This is a NOx sensor used in SCR (AdBlue/DEF) emission systems, responsible for measuring nitrogen oxide levels in exhaust gases before/after catalytic treatment.

FUNCTION:

• Measures NOx concentration in diesel exhaust
• Sends real-time data to ECU for SCR dosing control
• Optimizes AdBlue injection efficiency
• Helps maintain Euro 5 / Euro 6 emission compliance

INSTALLATION POSITION:

• SCR exhaust system (inlet or outlet depending on vehicle configuration)
• Typically mounted near DPF/SCR catalyst assembly in exhaust line

FAQ:

Q1: Is this inlet or outlet sensor?
A1: It can be used as either inlet or outlet depending on Mercedes SCR setup. Exact position must match OEM part number and vehicle configuration.

Q2: Which engines use it?
A2: Commonly used on Mercedes Bluetec diesel engines across OM642 / OM651 platforms in W205, W166, W221, X166 series vehicles.

Q3: What are failure symptoms?
A3: Check engine light, SCR/AdBlue warning, limp mode, incorrect NOx readings, or reduced engine performance.

Q4: Are all W205/W166/W221 sensors the same?
A4: No. Multiple NOx sensor versions exist depending on ECU software and SCR system revision. OEM matching is required.

Q5: Does replacement require coding?
A5: Some models require ECU reset or SCR adaptation after installation using diagnostic tools.