Used Mercedes-Benz X-Class Lambda Sensor

No — the Mercedes-Benz X-Class (2017–2020) was sold in the UK exclusively with diesel engines, and diesel engines do not use lambda (oxygen) sensors in the same way petrol engines do. Diesel exhaust systems use NOx sensors, temperature sensors, and DPF-related sensors instead, none of which are lambda sensors. If your X-Class has an engine management or emissions fault, you are most likely looking for a NOx sensor, exhaust temperature sensor, or a DPF pressure sensor — confirm the exact sensor code from your diagnostic report and describe that to the breaker.

On a petrol car, oxygen sensor and lambda sensor are the same thing, but the X-Class was never sold with a petrol engine in the UK, so neither term applies here. What diesel exhaust management systems use instead are NOx sensors (which measure nitrogen oxide levels) and exhaust gas temperature sensors, and these are what a diagnostic tool will typically flag on an X-Class. Take your fault code to a breaker and ask specifically for the sensor matching that code, as the correct part depends on its position in the exhaust system and the engine variant.

Fault codes in the P013x range relate to lambda or oxygen sensors, which are petrol-engine components, so this code appearing on a diesel X-Class usually points to a wiring fault, a faulty NOx sensor being misread by a generic code reader, or occasionally a diagnostic tool applying the wrong code definitions to a diesel system. It is worth having the vehicle re-scanned with Mercedes-specific diagnostic software (such as Xentry or iCarsoft MB) to get an accurate fault description before buying any parts. A breaker can help identify the correct sensor once you have a confirmed Mercedes fault code rather than a generic OBD-II code.

Trim level — whether Progressive, Power, or Stylish — does not affect which exhaust or emissions sensors are fitted; what matters is the engine variant and emissions standard the vehicle was built to. All UK X-Class models shared the same core diesel engine family (the 2.3-litre four-cylinder in 220d and 250d states of tune, and the 3.0-litre V6 in the 350d), and sensor fitment follows the engine code and emissions calibration, not the trim. Confirm your engine code and registration with the breaker so they can match the correct sensor from a donor vehicle.

The X-Class ran from 2017 to 2020 without a significant mid-life mechanical revision, but emissions calibration and sensor specifications can vary even within that short window depending on the engine code and the specific Euro 6 sub-standard the vehicle was built to. Because the X-Class never carried lambda sensors, this question most likely applies to NOx sensors or exhaust temperature sensors, and for those it is strong confirm-with-breaker territory — give the breaker your registration and engine code and ask them to cross-reference against the donor vehicle's details before agreeing a sale.