Mercedes A CL S W168 W215 W220 Petrol Lambda Oxygen Sensor Probe A0025400117

Mercedes A CL S W168 W215 W220 Petrol Lambda Oxygen Sensor Probe is an original exhaust system component from the Lambda sensors and O2 sensors category, designed for petrol engines. This used part allows for an economical yet professional repair of the air-fuel mixture control system in Mercedes vehicles, ensuring proper engine operation and compliance with factory specifications.

Specifications and technical data

• SKU: A0025400117
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A0025400117
• Substitutable numbers: A0025400117, A 0025400117, A 002 540 01 17, BG
• Fuel type: Petrol
• Category: Oxygen Sensors

Purpose and function in the petrol system

The lambda sensor in a petrol engine is responsible for the precise measurement of oxygen content in the exhaust gases, which allows the engine control unit to perform real-time fuel mixture corrections. As a result, the powertrain operates under optimal conditions, while fuel consumption and exhaust emissions remain at a controlled level. For Mercedes W168 and W220 models, a properly functioning O2 sensor is crucial for stable idle, correct throttle response, and efficient catalytic converter operation.

Benefits of using an original Mercedes lambda sensor

Using an original component from the Lambda sensors and O2 sensors category allows you to maintain the factory engine performance parameters. The sensor is structurally matched to the exhaust system and the engine control unit in your Mercedes, which reduces the risk of diagnostic errors and adaptation issues. A used OEM part is a particularly beneficial solution for servicing older vehicle generations, where both technical compatibility and reasonable repair costs are important.

In practice, replacing the lambda sensor restores correct fuel trims, reduces the risk of the check engine light coming on, and can positively influence the overall engine refinement. This is an important element for drivers who want to keep their car in good technical condition without the need for expensive modifications.

Condition, verification, and service application

The offered sensor is in used condition, meaning it has been removed from a vehicle and is intended for further use after proper installation. Such components are frequently chosen by workshops specializing in the Mercedes brand, especially when servicing youngtimer segment models, where the availability of new parts may be limited or economically unviable.

Before installation, a standard service procedure is recommended: checking the electrical wiring, inspecting the condition of the connectors, and verifying any potential leaks in the exhaust system. A properly installed lambda sensor works with the factory engine control unit, supporting stable operation of the petrol engine under various load conditions.

Selecting used electronics and sensors for Mercedes

When choosing used engine control system components – such as lambda sensors, ECUs, or other sensors – it is worth ensuring compatibility with the specific vehicle version and technical parameters. Manufacturer markings, OEM part numbers, and interchangeable numbers are helpful in verifying compatibility with a given model.

If you want to better understand when it is worth opting for used electronic components and sensors in your car, check out our guide: The second life of electronics – when is it worth choosing used engine ECUs, comfort modules, and parking sensors?

Expanding the exhaust gas measurement system in your Mercedes

If you are planning a comprehensive repair or upgrade of the engine area in your Mercedes and need other components from the same group, such as additional sensors before and after the catalytic converter, O2 sensors for other cylinder banks, or exhaust gas measurement elements, check the available parts in the Mercedes Lambda sensors and O2 sensors category.

For owners of older models of this brand who are planning a wider vehicle restoration using used components, the article on upgrading cars from the turn of the 90s and 2000s may also be helpful: The second life of a youngtimer – how used car parts rejuvenate cars from the 1998–2012 model years.