Used Peugeot 306 Lambda Sensor

Yes, petrol-engined 306s are fitted with at least one lambda sensor (also called an oxygen or O2 sensor), which sits in the exhaust system and helps the engine management system control the air-fuel mixture and reduce emissions. Diesel 306s do not use a lambda sensor in the same way, so if your car is diesel you are unlikely to need one. Check your V5 or ask a breaker to confirm your fuel type before ordering.

The Peugeot 306 ran from 1993 to 2002, with a significant facelift in 1997 that updated the bodywork and brought some engine revisions. The key fitment factors are the engine code and the number of wires on the sensor connector, not the facelift year itself, but sensors from pre-1997 and post-1997 cars may differ in connector type or thread pitch depending on which engine is fitted. Always quote your engine code to the breaker rather than just the year to make sure the sensor matches.

No, trim level does not affect lambda sensor fitment on the 306 — a Meridian, Cabriolet, or XSi with the same engine code as a base-spec car will use the same sensor. What matters is the engine code, the number of sensor wires, and the position in the exhaust (upstream before the cat, or downstream after it if a second sensor is fitted). Tell the breaker your trim name if it helps them locate the car on their system, but the engine code is what drives the part match.

Yes, it is relevant — on 306s fitted with a catalytic converter, some variants use two lambda sensors (one upstream and one downstream of the cat), so you need to know which position yours is in before ordering. Whether a specific sensor from one cat-equipped 306 will interchange with another is strong confirm-with-breaker territory, as catalyst generations and sensor specifications can vary. Give the breaker your registration and engine code and let them verify the exact position and connector type against their stock.

Almost certainly not without checking, because different engine capacities on the 306 used different engine management systems and may have different sensor thread sizes, connector types, or numbers of wires. A physically similar sensor from another 306 petrol engine could look identical but fail to communicate correctly with your ECU. Always match by engine code rather than engine size alone, and confirm with the breaker before buying.

Possibly, if both cars share the same engine code and the sensor specification matches, as Peugeot used shared powertrains across several models of the same era. However connector types, wire counts, and thread pitches can differ even between cars using nominally similar engines, so this is not something to assume. Give both registration numbers and engine codes to the breaker and let them cross-reference before committing to the purchase.