Here is what the Workshop Manual says:
P2275-00
O2 Sensor Signal Stuck Rich - Bank 1, Sensor 3, No sub type information:
Heated oxygen sensor
circuit, short circuit to
ground, short circuit
to power, open circuit,
high resistance
Air leakage between
heated oxygen sensor
and catalyst
Heated oxygen sensor
tip damaged
Heated oxygen sensor
tip blocked
Heated oxygen sensor
tip contaminated by
excessive oil
consumption
Heated oxygen sensor
tip contaminated by
poor or incorrect fuel
Using the Jaguar
Land Rover approved
diagnostic equipment
check datalogger
signal - Oxygen
Sensor (O2S) Voltage
Bank 1 Sensor 3
(0x0360)
Heated oxygen
sensor signal for
correct operation
Refer to electrical
circuit diagrams and
check the heated
oxygen sensor circuit
for short circuit to
ground, short circuit
to power, open
circuit, high resistance
Check heated oxygen
sensor is correctly
installed
Check heated oxygen
sensor for tip damage
Check heated oxygen
sensor for tip blocked
Check heated oxygen
sensor for tip
contamination by
excessive oil
consumption. Carry
out oil consumption
check
Check heated oxygen
sensor for tip
contamination by
poor or incorrect fuel.
Check customer is
using correct grade of
fuel

As far as I can figure out all this means that your Bank 1 Sensor 3 oxygen sensor is kaput and needs replacing.
I forget which bank is Bank 1 but I'm 99% sure that Sensor 3 is the post-cat sensor, ie the last one in the line (rearmost in the exhaust system) and is fairly easy to replace.
I also vaguely remember a thread or two around here where someone else has already replaced this particular O2 sensor.

 

 

Oxygen sensor is a warranty covered item. I had a P0042 code, Bank 1 #3 Oxygen Sensor bad. It was covered under my extended warranty. The #3 oxygen sensor is located after the catalytic converter and tells the computer how effective the catalytic converter is cleaning the exhaust. It does not effect the fuel mixture or the performance of the motor. It is safe to drive. However that obnoxious CEL will not go away and could mask other potentially damaging codes. You should get it in ASAP to be replaced. I checked my codes once a day after driving to make sure no other codes were popping up. I drive aggressively in sport mode with no ill effects. Beautiful car BTW.

 

Maybe I should invest in a code reader. Do you have a preference on which one. I have a service appt early next week. Thanks