Used Mercedes-Benz CLS Oxygen Sensor

It depends on the fuel type: petrol-engined CLS models do have lambda (oxygen) sensors fitted in the exhaust system, typically before and after the catalytic converter, and these are a genuine used part worth searching for. Diesel CLS models, however, do not use oxygen sensors in the same way — diesels rely on other sensors such as NOx sensors or exhaust temperature sensors for emissions management, so if your CLS is a diesel you are likely looking for a different part entirely. Check your V5C or registration plate lookup to confirm your fuel type before ordering.

These are two distinct generations — the W219 ran from 2004 to 2010 and the W218 from 2011 to 2018 — and while some engine families overlap across them, the exhaust layouts, sensor positions and connector types can differ, so a direct swap cannot be assumed. The key factors to match are the specific engine code (for example M272 or M276) and the sensor position (pre-cat or post-cat), not just the generation. Always confirm the engine code from your V5C and check with the breaker that the sensor matches yours precisely before buying.

Trim and badge name alone do not determine fitment — what matters is the engine code, because the 350, 500 and 55 AMG all used different engines with different exhaust configurations and different numbers of sensors. The CLS 55 AMG in particular uses a supercharged V8 which will have a distinct exhaust and sensor setup compared to the V6 in the 350. Match the engine code exactly and confirm with the breaker rather than assuming badge-to-badge compatibility.

Both years fall within the W218 generation (2011–2018), so the body generation is the same, but fitment of an oxygen sensor depends on whether the engine codes match and whether the vehicles are from the same emissions era. The W218 spanned Euro 5 and Euro 6 boundaries, and the exhaust sensor calibration can differ across those standards, so a 2011 sensor and a 2014 sensor may not be interchangeable even if the engine family looks similar. Confirm the engine code and emissions standard with the breaker against your specific registration before proceeding.

The W218 received a facelift in 2014, and while many mechanical components carried over, the facelift period coincided with the transition to tighter Euro 6 emissions standards on some engine variants, which can affect exhaust sensor calibration and specification. Whether the pre- and post-facelift sensors are interchangeable on your specific engine is not something that can be confirmed as a blanket rule — it depends on the engine code and the emissions standard your vehicle was homologated to. Supply your registration and engine code to the breaker so they can check the specific part number rather than going on model year alone.

Trim level — whether SE, AMG Line or Sport — does not affect which oxygen sensor is fitted, as the sensor is determined entirely by the engine and emissions specification, not by interior or exterior trim choices. You may find cosmetic differences in the exhaust tips or body styling between trims, but the sensor itself in the exhaust system will be the same across trims sharing the same engine code. Focus on matching the engine code and sensor position (upstream or downstream of the catalytic converter) rather than the trim name.