Lambda sensor/LPG

[plewis268]

My 35,000 mile 2004 petrol Bongo went in for LPG conversion, after which the engine warning light stayed on after starting the vehicle. The LPG mechanic told me it was the lambda sensor and demonstrated how to extinguish the light by starting the engine, then stopping it, then restarting it. Then the light would go out with all the other lights. He says it is a fault of the lambda sensor and insists it has nothing to do with the LPG conversion, and is simply a coincidence. Is there a possible connection? He is going to test the lambda sensor again next week at my insistence before I have to buy a new one. Does anyone have an impartial answer? Thanks.

[rita]

The simple solutions is.. let the mechanic/garage "Supply" and fit the sensor on the condition that if it doesn't cure the fault you don't pay for time or material .

[Ian]

Be aware that lambda sensors on 2003 Bongos or later are different than earlier versions.

[Simon Jones]

The Lambda sensor only measures the amount of oxygen in the exhaust gas so if it does not show a fault when running on petrol then that suggests the problem is specific to running on LPG. I guess it's possible the sensor or emissions are on the borderline. Can he connect up the gas analyser to the exhaust and monitor the Lambda readings on petrol and gas? I suspect there will be quite a difference between the two readings which would indicate the ECU needs tweaking.

You can buy a universal sensor for £50 while the genuine one is considerably more.

[rita]

With plewis268,description of the fault and temp cure I would imagine that the engine is running on Petrol at that specific time.

[rita]

Be aware that lambda sensors on 2003 Bongos or later are different than earlier versions.

Good information, do you have the Mazda part numbers for the later version sensors.

[Ian]

Earlier 2.0 litre Bongos up to VIN S***-59999 part number FEMJ18961

Later Bongos FF5518861

[plewis268]

Thank you all for your help and advice. My usual garage along the road is run by an ex-Mazda mechanic who got me a Mazda 6 sensor and modified it to fit. just been around the block in it, but all seems well so far. The light goes out now. It cost about half as much as the Bongo sensor would have with labour as well. Keeping our fingers crossed anyway. Looking good so far, but will post again if there are any problems.