Can anyone shed any light on which models have one of these fitted? I've only found them on US sites which leads me to think they are just on GEMS disco 1's.

They are supposedly located in the air filter box. If anyone's got one has it ever gone wrong and what were the symptoms?

Gems D1's and the D2 has it too with Motronic. The part numbers may be different for these two but the sensor isn't available for the 14CUX.
JC

Thanks Justin,

One more thing I can rule out! I've still not sorted my problem as it's been loaned out for the last few weeks but apparently the idle/stalling issue is still there.

I've got it narrowed down to (in no particular order):

VSS
Ignition Amplifer
Coil
Fuel Temp Sensor
Sticky Valves
Blocked (or worn?) injectors

Going to have to take it back to the main dealer, but they're useless as well as a rip off so will be good to give them some ideas......