Mercedes-Benz S-Class Lambda Sensor Replacement Parts

Yes, but only on petrol-engined variants — the lambda (oxygen) sensor sits in the exhaust and feeds the engine management system to regulate the air-fuel mixture, so it is an essential component on every petrol S-Class. Diesel S-Class models (such as the S 320 CDI, S 350 CDI, and S 400 CDI) do not use a lambda sensor in the same way, as diesel combustion management works differently. If you have a diesel S-Class and your diagnostic code is pointing at an exhaust gas sensor, confirm with the breaker whether your engine actually carries a lambda-type sensor or a different sensor such as an NOx sensor.

The W220 ran from 1998 to 2005 and the W221 from 2006 to 2013, and these are distinct generations with different engine families, engine management systems, and exhaust configurations, so the sensors are generally not interchangeable. Even where the physical connector looks similar, the calibration and resistance characteristics can differ between generations and will cause fault codes if mismatched. Always quote your engine code — found on your V5C or inside the engine bay — to the breaker rather than just the generation name, as the same W221 bodystyle covered several different petrol engines.

The W221 received a facelift in 2009, and while the visual changes were largely cosmetic, some engine variants were updated at the same point and moved from Euro 4 to Euro 5 emissions compliance, which can affect sensor specification. The trim level — S 350, S 500, S 600 and so on — does not in itself determine which sensor fits; what matters is your specific engine code and the emissions standard your car was built to. Name the facelift year to your breaker, give them your registration and engine code, and ask them to confirm the sensor specification matches before buying.

Trim designation alone does not determine fitment — what actually matters is the engine code, which can differ even within the same badged variant across model years. That said, the S 63 AMG uses a different engine entirely (a high-output V8 biturbo) compared with, say, the S 350's V6 petrol, so sensors from those two are very unlikely to be interchangeable. Give the breaker your engine code rather than just the trim name, and they can cross-reference the correct sensor position (pre-cat or post-cat) and connector type for your specific engine.

The W222 replaced the W221 from 2013 onwards and introduced Euro 6 emission standards alongside updated engine management systems, meaning the sensor specifications changed significantly at that generational boundary. A sensor from a W222 is very unlikely to be compatible with a W221's earlier engine management system even if the connector physically resembles the older part. Always confirm with the breaker using your registration and engine code, as mixing sensors across a Euro 5 and Euro 6 boundary can cause persistent fault codes and may create MOT complications.

Most petrol S-Class engines carry at least two lambda sensors per exhaust bank — one upstream (pre-catalyst) and one downstream (post-catalyst) — and V8 or V12 engines with two exhaust banks can have four or more sensors in total. The upstream and downstream sensors have different functions and often different part numbers, so buying the wrong position will result in fault codes even if the connector fits. Tell the breaker not just your engine code but also which sensor position you need — NS or OS if it is a twin-bank engine, and pre-cat or post-cat — so they can supply the correct unit.