Cheap Mazda CX-30 Oxygen Sensor

Yes, but only on petrol-engined variants — the 2.0-litre Skyactiv-G petrol and the 2.0-litre mild-hybrid (M Hybrid) use conventional lambda/oxygen sensors in the exhaust system to manage fuelling and emissions. The 2.0-litre Skyactiv-X (SPCCI) engine also uses oxygen sensors as part of its emissions management. If your CX-30 is a diesel, there is no diesel variant of the CX-30 — Mazda never offered one — so if you are unsure which engine you have, check your V5C or registration plate data before ordering.

The CX-30 launched in the UK in 2019 and has remained on a single generation without a major structural facelift that changed the engine or exhaust architecture, so sensors from cars within the same engine code family are often compatible across those years. However, emissions calibration and sensor specification can be revised during a model run, so you should always confirm the engine code on both the donor and recipient vehicle with the breaker before buying. A sensor that physically fits but carries a different calibration can trigger warning lights or affect fuelling.

Trim level does not affect oxygen sensor fitment on the CX-30 — SE, SE-L, GT Sport, and Homura all share the same exhaust and sensor positions for a given engine. What matters is the engine code and model year, not whether the donor car had leather seats or a sunroof. When contacting a breaker, quote your engine code rather than your trim name.

No — the upstream sensor ahead of the catalytic converter and the downstream sensor after it are different parts with different operating ranges, and fitting the wrong one to the wrong position will cause faults. When sourcing from a breaker, specify which sensor position you need (upstream or downstream) and confirm the engine code so they can pull the correct unit from the donor car.

Whether a catalytic converter from a specific donor year or engine variant correctly interchanges with your car is strong confirm-with-breaker territory, as emissions-era specifications, substrate calibration, and MOT compliance all depend on the exact details of both cars. Give the breaker your full registration so they can cross-reference the donor vehicle's engine code and emissions certification against yours. Never assume a visually identical cat is an emissions-equivalent match.

Mazda does use shared Skyactiv-G engine families across models, so it is possible that a sensor with the same engine code and sensor position specification could cross over, but this is not guaranteed because exhaust routing, sensor thread pitch, and connector types can differ between platforms. Always give the breaker both the donor model details and your CX-30 registration so they can verify compatibility rather than assuming a shared engine means a shared sensor. Cross-model sourcing can work but carries more risk than like-for-like replacement.