I am posting this in case it is useful.




I needed to replace one of my upstream O2 sensors. Very uncharacteristically for Jaguar, you can actually get reasonable access to them!
I decided to do the right thing and purchase an O2 Sensor socket. Despite having the 'correct tool for the job', as I was attempting to loosen the old sensor, I could feel the socket spreading under the load. It was fairly obvious that, if nothing else, I was going to lose skin off my knuckles when the whole thing slipped.
But there is a bit of space, so I got out my trusty vice grips and clamped them over the socket, as shown in the photos.


The result was no springing, no lost skin off knuckles and a nicely removed sensor.

 

good tip ... lateral thinking has it's rewards

 

I also had that fiasco.

Trusty "Shifter", or Crescent in some languages, or Adjustable in other languages, had it out in 10 seconds. Took longer to unplug the socket connector.

 

I hear pouring JD on the things loosens them up quite nicely.

(note to the inexperienced: not being serious here!)

 

I had JD for MY inner lube prior to that task, worked for me.

The inexperienced, I trust you mean in the PROPER use of JD, not in the actual mechanical experience??

 

I always use a thin layer of anti seize applied with a Q-Tip on the upper half of the O2 sensor threads when installing new.

 

Sort of.

I was thinking of a future novice with three posts stumbling
across this thread who did not know of the illustrious history
of JD inspired moments on JF.

 

Another way to remove the bad sensor is to cut the wire, then you can use a 22mm ring spanner.

 

I agree, BUT, the "SEARCH" should find it, NO??

Then I forget, there are just so many that have NOT come from a V12 to a "Modern", so the intake of such lubricant is simply lost on them, as is the language.

 

Being new to OBD II cars, I am still building my trust sufficiently to really believe the car's self-diagnosis. What if it is wrong? By cutting off the connector I'd be ruining a perfectly good sensor!


I have to admit, though, that this makes two out of two for OBD - the sensor was faulty this time and so was the coil pack the car self-diagnosed last year.


So maybe next time I will believe the car and just cut the connector off so that I can use a 7/8 ring spanner.

 

Worst case you could solder the wires.

But you can use a meter (DVOM) first at the plug to see at least if the heater is a sane ohms (compare with other side but should be about 1ohm) as it's often the heater that finally burns out (the code more or less tells you of course).

 

Not exactly. O2 sensors are normal wear and tear items. They need to be replaced at specified intervals even if "good". Those intervals can be a little optimistic, though. There's no harm done in replacing them early, especially if suspect, or if they are of unknown age.

The early model ('99-02) sensors are not expensive at all. The later model sensors are more spendy.

 

While I could be tempted to do 'routine maintenance' replacement of the upstream sensors, looking at the location of the downstream ones, I think I may be more inclined to wait until I am forced to do a change-over!