Mercedes W204 C207 W212 Lambda Probe Oxygen Sensor M271 Petrol A0035428518

Mercedes W204 C207 W212 Lambda Probe Oxygen Sensor M271 Petrol is a component from the Lambda probes and O2 sensors category, designed for M271 petrol engines in selected Mercedes models. Using this sensor allows for an economical yet technically correct repair of the air-fuel mixture control system, while maintaining the factory performance characteristics of the engine.

Specifications and technical data

• SKU: A0035428518
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A0035428518
• Substitutable numbers: A0035428518, A 003 542 85 18
• Fuel type: Petrol
• Category: Oxygen Sensors

Function of the lambda probe in the M271 petrol engine

The lambda probe in a petrol engine is responsible for measuring the oxygen content in the exhaust gases and sending a signal to the engine control unit (ECU). Based on this signal, the ECU corrects the fuel dosage, keeping the mixture in the optimal range. A properly functioning O2 sensor supports stable idling, correct acceleration, and reduced fuel consumption.

In M271 units, using the appropriate sensor from the Lambda probes and O2 sensors group is crucial for maintaining compliance with factory injection maps and ensuring the correct operation of the catalytic converter. Replacing a worn-out probe with a functional unit restores the proper response of the control system and helps reduce the risk of diagnostic errors.

Benefits of using an original probe in Mercedes W204, C207, W212

Using a probe dedicated to specific Mercedes models with the M271 engine ensures electrical and mechanical compatibility with the wiring harness and exhaust manifold. A properly selected O2 sensor provides:

• a stable voltage signal across the full range of engine loads,
• compatibility with the factory ECU software,
• correct air-fuel mixture regulation in closed-loop mode,
• exhaust emissions limited to the level intended for the specific model.

For the user, this means a more predictable throttle response, smooth engine operation, and the ability to perform effective diagnostics using standard service tools.

Product characteristics and application

The presented lambda probe is designed for petrol fuel systems compatible with the M271 engine used in Mercedes C-Class (W204), E-Class (W212), and C207 body styles. The sensor design is adapted to operating conditions in the exhaust stream, featuring a properly selected measuring element and a housing resistant to high temperatures.

The product is sourced from dismantling, which allows for an excellent price-to-functionality ratio. For workshops and individual users, this is a solution that enables the restoration of proper combustion control system operation without the need to invest in a new part, while maintaining the original installation specifications.

Selection, diagnostics, and installation of the lambda probe

To select the correct lambda probe for a specific vehicle, it is recommended to use the manufacturer's markings, the VIN number, and the engine control unit parameters. Proper identification eliminates the risk of compatibility issues with the electrical wiring or the mounting thread in the exhaust system.

Before installation, it is recommended to verify the system for mechanical damage, leaks, and the condition of other exhaust system components. A properly performed probe replacement, using appropriate tools and anti-seize paste on the thread, facilitates future service and reduces the risk of damaging the socket.

If you want to better understand how to safely use used sensors and control modules, how to check their compatibility, and what to pay attention to during installation, check out our guide: Used automotive electronics on board – why is it worth choosing second-hand ECU modules and sensors?

Expanding exhaust control system service in 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 oxygen sensors, control probes, or diagnostic probes, check out the available parts in the Mercedes lambda probes and O2 sensors category.

By using properly selected components from this group, it is possible to restore the consistent operation of the entire combustion control system, which translates into better engine refinement, more predictable performance, and the maintenance of emission parameters at the levels intended by the manufacturer.