Jaguar Repair: 1986 Jaguar XJ6, propane torch, 1986 jaguar xj6

Question
QUESTION: Hi Howard,

My oxygen sensor light has come on. Where is the sensor located and how difficult is it to replace?

Thanks for you help,
Judy

ANSWER: Hi Judy,

Are you talking about the mileage indicator light? If so the reset is on the reset box to the left of the ECU in the trunk under the forward trunk cover.

The O-2 censor is in the exhaust under the hood on the driver's side.

Howard

---------- FOLLOW-UP ----------

QUESTION: Hi Howard,

No the light that came on and stays on defiantly says oxygen sensor. The car is running fine but the light stays on. My XJ6 has 61000 miles on her. What does this light mean? What do you recommend I do first?  

Thanks,
Judy

Answer
Judy, I believe they recommend that the O-2 censor be replaced at a specific mileage so I would go in the trunk like I suggested and reset the trip meter and if that puts the light out stop in your local Jaguar repair shop and have them test the out put of the O-2 censor.

The light is just a warning light that Jaguar recommends changing the O-2 censor but it does not mean that it is bad. I have the old style (one wire)in one of my Jags that has over 100,000 miles on it and it still works. The newer style (which your car may have is a 3 wire O-2 censor)
It operates the same except they added an electric heater so that it will start operating if the O-2 censor drops below 600 Degrees F. and when you first start up. The O-2 censor is just a trim device for the injection system and is not a major influence on injection.

You can test it by putting a volt meter on low DC volts and pass a propane torch across the tip and watch the volt meter for a response. If you have the 3 wire one, the blue wire is the O-2 censor and the White w/green and the black wires are the two heater wires. Just connect your + prob of the volt meter to the blue wire and your - prob to the case of the censor and pass the propane torch across the tip.

When the O-2 censor is in operation on the car it produces about .5v if the injection system is correct. If the voltage is high (.7 to 1.0v) the fuel mixture is too rich and .3v and below is too lean. Some mechanics who don't have HC/CO test equipment use the O-2 censor reading to adjust fuel mixture.

Howard