Newer lambda sensors tend to have a pre heater to warm them up quicker to help reduce emissions being too high from cold. If the heater fails then the ecu would probably pick it up as a fault. The Gems system on my Plus 8 did this and the OBD tester showed the fault correctly as a heater circuit failure. Luckily the Autel Maxiscan had the ability to do running checks and voltage readings from the sensors confirmed which of the two downstream sensors was faulty. Being downstream of the Cat meant the engine was unaffected as the upstream ones did that job. The downstream ones just checked the effectiveness of the cats themselves. The only problem was getting the old one out ! I jibbed out and got the garage to do it and also put a new sump gasket on at the same time. Easier than me crawling under the car.
I’ve still got a spare sensor so when I get round to sorting the trad parts I have I’ll sell them on.
I might check if the Maxiscan works on the Plus Four. It’s not upgradable for software any more so might not link. It has proved a good time, effort money saver over the years. My 1993 4/4 had a Ford 3 pin OBD system and I had a Draper reader for it. Never needed and sold years ago.
Last edited by sospan; 26/03/24 06:56 PM.
