Mercedes W164 W211 W221 OM642 Front NOX Sensor L=615MM SiemensVDO A0035428818

Mercedes W164 W211 W221 OM642 Front NOX Sensor L=615MM SiemensVDO is a specialized nitrogen oxide sensor designed for Mercedes diesel engines with the OM642 unit, installed in the front part of the exhaust system. As a component from the Lambda Sensors and O2 Sensors group, it is responsible for precise measurement of exhaust gas composition, supporting the correct operation of the exhaust gas purification system and the engine control unit. The used SiemensVDO OEM component allows for a technically correct replacement of the factory sensor without altering the installation's structure.

Specifications and technical data

• SKU: A0035428818
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A0035428818
• Substitutable numbers: A0035428818, A 003 542 88 18
• Location on the vehicle: Front
• Fuel type: Diesel
• Category: Oxygen Sensors

Purpose and Function of the NOx Sensor

The front NOx sensor in the OM642 diesel engine monitors the nitrogen oxide content in the exhaust gases before exhaust purification components such as the catalytic converter or emission reduction system. Based on its signal, the engine control unit adjusts the fuel injection, the injection system's operation, and the emission reduction strategy, which translates into stable engine operation, reduced smoke, and compliance with emission standards.

In Mercedes W164, W211, and W221 vehicles, a properly functioning NOx sensor is crucial for:

• maintaining the correct operation of the diesel engine's exhaust gas purification system,
• reducing the risk of the engine entering limp mode,
• preserving the appropriate dynamics and smoothness of the OM642 unit's operation,
• proper cooperation with the engine control unit's software.

Construction and Compatibility with Mercedes Models

The offered NOx sensor is designed for installation in the front part of the exhaust system, in accordance with the factory location designated by the vehicle manufacturer. The integrated cable of a specific length ensures proper routing of the harness from the exhaust sensor to the electronic module, without strain or risk of mechanical damage.

As an OEM SiemensVDO component, the sensor is structurally adapted to the electrical system and control unit used in OM642 engines in W164, W211, and W221 body styles. The appropriate connector and mounting geometry allow for installation in place of the factory component without the need for modifications, which is important for both reliability and subsequent service diagnostics.

Benefits of Using an Original NOx Sensor

Using an original NOx sensor in a diesel engine brings tangible operational benefits. A correctly functioning component allows for:

• stable engine operation without undesirable RPM fluctuations,
• reducing the risk of exhaust emission-related errors appearing in the control unit's memory,
• maintaining optimal fuel consumption thanks to proper mixture composition correction,
• preserving the efficiency of the exhaust gas purification system in the long term.

For Mercedes vehicle owners, it is particularly important that the original NOx sensor works with the factory control unit software without the need for map modifications or additional programming beyond standard service adaptation.

Characteristics of a Used Product

The offered NOx sensor is a used component, allowing for economical repair of the exhaust emission system while maintaining the original manufacturer's specifications. Such components are often chosen for vehicles used intensively, where a reasonable service cost is important while maintaining correct functionality.

Before installation, a standard service procedure is recommended, including checking the electrical system, connector condition, and potential adaptation in the engine control unit according to the vehicle manufacturer's guidelines. This ensures that the sensor's full potential can be utilized and the correct operation of the exhaust emission system can be restored.

Support in Selection and Additional Materials

The selection of the appropriate NOx sensor for a specific diesel engine version and body style should always be based on the vehicle's identification data and part numbers. Especially for electronic components such as sensors and control modules, hardware and software compatibility is crucial to avoid communication problems with the engine control unit.

If you are planning a comprehensive repair or upgrade of the engine area in your Mercedes and need other parts from the same group, such as lambda sensors, additional O2 sensors, or related measurement components, check the available parts in the Mercedes Lambda Sensors and O2 Sensors category.

To better understand how to safely use used sensors and electronic modules, including exhaust emission system components, it is worth reading the Global Parts guide: Used Car Electronics Onboard – Why Choose Second-Hand ECUs and Sensors?