Second Hand Mercedes-Benz GLS Lambda Sensor

Yes, but only on petrol-engined GLS variants — the GLS 400, GLS 450, GLS 500, and GLS 580 all use lambda (oxygen) sensors as part of their exhaust management systems. Diesel GLS models (GLS 350d, GLS 400d) do not use lambda sensors in the same way; diesel engines rely on different exhaust after-treatment technology including NOx sensors and AdBlue systems instead. If you drive a diesel GLS and are chasing an emissions or exhaust fault, confirm with the breaker exactly which sensor you need against your registration.

The GLS has run across two generations: the first generation (X166) ran from 2016 to 2019, and the second generation (X167) launched in 2019 and remains current. These generations use different engine families — for example the X166 used the M276 V6 petrol, while the X167 moved to updated M256 and M176 units — so lambda sensors from an X166 are very unlikely to suit an X167 and vice versa. Always confirm the engine code on your specific registration with the breaker before buying a used sensor.

Trim level and interior specification make no difference to lambda sensor fitment — what matters is the engine code and the model year, not whether your car is an AMG Line or a standard specification. However, the GLS 450 and GLS 580 use different engines (the M256 straight-six versus the M176 V8), so sensors between those two variants will not interchange even within the same generation. Tell the breaker your engine code and registration rather than just the trim name.

The 2019 changeover from the X166 to the X167 brought a new platform and substantially revised engine line-up, making direct sensor interchange across this boundary unlikely. Both generations used Euro 6 emissions standards, but the specific sensor design, wiring connectors, and thread pitch can differ between engine families even where the emissions era is the same. Confirm any cross-generation fitment directly with the breaker against both registration numbers before purchasing.

Yes — petrol GLS models typically run multiple lambda sensors per engine, usually pre-catalytic converter (upstream) and post-catalytic converter (downstream) sensors, and a V8 like the GLS 580 will have more sensors than a straight-six GLS 450 due to its twin-bank exhaust layout. Getting the correct position (upstream or downstream, NS or OS bank) is just as important as matching the engine code, so be precise when describing your requirement to the breaker. Fitting an upstream sensor in a downstream position or vice versa will cause running and emissions faults.

Both the 2017 and 2018 GLS 400 fall within the first-generation X166 and share the same M276 V6 engine family, so in principle the lambda sensor specification should be consistent across those years. That said, minor mid-production revisions can occasionally affect sensor part numbers, so it is always worth having the breaker cross-reference the part number against your specific registration to be sure. Never assume fitment purely on year and badge — confirm with the breaker before you commit.