HI Dave,
Yep definitely the lambda sensor,I bought a code reader & hooked it up & sure enough P1000 was the reading so
checked the code to find you were right mate. I also got a reading of 1467 which showed a sensor located under
the air filter but my mechanic said both readings were connected to the lambda. He also told me to clear the faults
on my reader & said once cleared leave the engine turning over for half an hour which would give the ecu a chance
to update but even if the light comes back on not to worry as it won,t affect the car in any way.
I like to keep things pristine on my jag so I,ve asked the mechanic to change the plugs & put a new lambda
sensor onto it.