Peugeot 307 Lambda Sensor Replacement Parts

Yes, all petrol-engined Peugeot 307s have at least one lambda sensor (also called an oxygen sensor), as they are required for the engine management system to control the fuel mixture and meet emissions standards. Diesel 307s do not use lambda sensors in the same way — the diesel combustion process does not rely on them, so if your 307 is a diesel you are likely looking for a different sensor such as a NOx sensor or a diesel-specific component. If you are unsure which fuel type your car is, check your V5C or registration plate history before ordering.

The 307 ran from 2001 to 2008, with a facelift arriving in 2005 that brought updates to the interior and exterior but used largely the same platform and engine family. Lambda sensor compatibility is determined by the engine code rather than the facelift year, so a pre-facelift and post-facelift 307 with the same engine code — for example both running a 1.6 petrol with the same code — will often use the same sensor. However, you should confirm the exact engine code from your V5C and check it against the donor car's engine code with the breaker before buying, as even small engine revisions can change the sensor specification or connector type.

Trim level does not affect lambda sensor fitment — the sensor is determined by the engine code and emissions specification, not whether the car is an S, SE, XT, XSi, or any other 307 trim. The 307 SW is an estate body variant, but again body style makes no difference to the exhaust or sensor specification. Confirm the engine code matches between donor and recipient car, and your breaker can cross-reference that for you.

Most petrol 307s have two lambda sensors — one upstream of the catalytic converter (the pre-cat or 'front' sensor) and one downstream (the post-cat or 'rear' sensor), and these are not interchangeable with each other even though they may look similar. The upstream sensor controls fuelling in real time and is typically more expensive, while the downstream sensor monitors catalyst efficiency. Tell your breaker which position you need — upstream or downstream — alongside your engine code, so they can supply the correct unit.

A correctly matched lambda sensor — right engine code, right position (upstream or downstream), from the same emissions era — should not cause an MOT failure on its own, as the 307 predates Euro 5 and Euro 6 boundaries that can affect later vehicles. That said, a visually similar sensor from a different engine variant or with a mismatched connector can trigger fault codes and cause a failure on emissions grounds, so fitment accuracy matters. Always confirm the engine code and sensor position with your breaker, and if any catalytic converter work is also involved, treat that as separate territory to confirm carefully with the breaker against your registration.

Different engine sizes in the 307 petrol range — such as the 1.4 and 1.6 — typically have different engine codes, and lambda sensors are matched to the engine code rather than just the displacement. Using a sensor from a different engine variant risks a connector or calibration mismatch that can cause running problems or emissions failures even if the sensor physically fits. Give your breaker both your exact engine code (found on your V5C or on a plate in the engine bay) and the position you need, and they will be able to confirm whether a donor part from a different variant is suitable.