Used Mercedes-Benz GLA DPF

The GLA has run across two main generations — the X156 (2013–2020) and the H247 (2020 onwards) — and these are entirely different platforms, so a DPF from one generation will not transfer to the other. Even within the X156, there was a facelift in 2017 that brought engine revisions, and a DPF from a pre-facelift X156 may not suit a post-2017 car even if they look similar under the car. The critical factors are the engine code and the emissions standard (Euro 5 or Euro 6), not the model year alone. Confirm the engine code on both donor and recipient vehicles with the breaker before buying.

This question spans the 2017 X156 facelift, which is an important boundary — the 2016 car is pre-facelift and the 2018 is post-facelift, and engine specifications and emissions calibration could differ between them. Both sit within the X156 generation, so physical dimensions may appear similar, but a DPF matched to the wrong emissions tune can cause sensor faults or MOT failures. You'll need to match engine codes exactly, not just model years. Confirm with the breaker that the part number or engine code aligns with your specific registration before purchasing.

Trim level — whether AMG Line, Sport, Executive, or any other — does not affect which DPF fits your GLA; the exhaust and emissions system follows the engine and the emissions era, not the badge on the tailgate. What you may find is that higher-spec cars have different exhaust tip finishers or trim surrounds, but the DPF itself is determined by the engine code and Euro emissions standard. So don't rule out a DPF from a different trim grade — focus on matching the engine code instead. Just be aware that any decorative exhaust trim from the donor car may not match your vehicle's finish.

The engine code is the single most important piece of information when sourcing a used GLA DPF — common diesel units in the X156 generation include the OM651 four-cylinder used in earlier 220 d models and the OM654 that arrived with the Euro 6 updates, though exact fitment years for each variant should be confirmed against your V5C or with the breaker. The DPF is calibrated to work with a specific engine's exhaust gas temperatures and flow rates, so fitting one from the wrong engine family risks poor regeneration and warning lights. Pull your engine code from the V5C document or the engine bay sticker and quote it directly to the breaker. Never rely on model year or trim name alone to establish compatibility.

Euro 5 and Euro 6 DPFs are not interchangeable — the Euro 6 standard requires tighter particulate filtration, and the associated sensors, backpressure thresholds, and ECU maps are calibrated differently between emissions eras. Fitting a Euro 5 unit to a Euro 6 car is likely to trigger fault codes and could result in an MOT emissions failure, as well as potentially affecting the car's AdBlue or NOx reduction system if fitted. The GLA X156 generation spanned both Euro 5 and Euro 6 production, so two visually identical cars from different years may need completely different DPFs. Always confirm the emissions standard of the donor vehicle matches yours — the breaker can cross-reference this against your registration plate.

A used DPF can be a cost-effective repair, but the condition of a used unit is harder to verify than most other parts — a DPF that has been allowed to block or has been chemically damaged may show no obvious external signs. Ask the breaker where possible about the mileage of the donor vehicle and whether any DPF warning lights were present before the car was dismantled. Confirm the engine code and emissions era match your car exactly, as outlined in the other questions here. It is also worth having the unit inspected or flow-tested by a specialist before fitting if you have any doubts about its condition.