Second Hand Mercedes-Benz GLS Oxygen Sensor

This depends entirely on the engine: petrol GLS variants (such as the GLS 350d's petrol counterparts and the GLS 500/GLS 580) do carry lambda/oxygen sensors as part of their exhaust management system, but diesel GLS models (including the GLS 350d and GLS 400d) do not use traditional oxygen sensors — diesels use NOx sensors and exhaust gas temperature sensors instead, so if you drive a diesel GLS you are likely looking for a different part. If you are unsure which sensor your vehicle actually needs, confirm with the breaker against your registration before ordering.

The X166 GLS ran from 2016 to 2019 and the X167 replaced it from 2019 onwards, and these generations use different engine families, exhaust layouts, and emissions calibrations, so sensors are not a straightforward swap across that boundary. Engine code is the key variable — confirm the exact engine code on both donor and recipient vehicles with the breaker before purchasing, as a physically similar sensor from the wrong generation may cause fault codes or fail to meet the emissions mapping your ECU expects.

No, trim level does not affect oxygen sensor fitment on the GLS — AMG Line, AMG Line Premium, and base specification cars with the same engine code will use the same sensor. What matters is the engine code, fuel type, and emissions standard (Euro 6 for all UK GLS variants), not whether the car has different wheels, interior finish, or badging, so do not pay extra or search differently based on trim alone.

Yes, position matters significantly: upstream (pre-catalytic converter) and downstream (post-catalytic converter) oxygen sensors have different calibrations and connector configurations, and fitting the wrong one will typically generate fault codes and may affect fuelling. When contacting a breaker, specify whether you need the nearside or offside sensor if applicable, and whether it is the upstream or downstream unit, ideally quoting your engine code and the OEM part number if you have it.

The GLS 500 across the 2016–2019 X166 generation used the same M276 V6 biturbo petrol engine family throughout, so a sensor from a 2017 and a 2018 car of identical engine code is likely to be compatible, but you should still verify the engine code and sensor position with the breaker before buying. Small production-run changes can affect connectors or calibration values, so always cross-reference the OEM part number against your registration rather than relying on year alone.

The GLE and GLS share several engine codes across their generations, so there is a reasonable chance of compatibility on matching engine variants, but exhaust routing and sensor mounting positions can differ between the two body styles, meaning a direct swap is not guaranteed. Provide the breaker with your GLS's exact engine code and registration so they can compare against the donor GLE part — do not assume compatibility based on shared engine family alone.