Just another twist on this story. If I drive with the A/C on, it doesn't stall. It seams the slightly increased idle speed is enough to stop it stalling. Is there any way to adjust the idle speed on these engines?
Taking it back to the dealer tomorrow but I'm not holding my breath for them to come up with a solution!

 

you may just need to clean out your TB for that matter ever done that?

programer can adjust the idle

 

Never cleaned the throttle body but fitted a Fast Man one a year or two back.
Took it to the dealer this morning and about half way there I noticed it was driving perfectly! It wasn't just not stalling, it didn't hunt or feel like it was going to stall. Carried on to the dealer where suprise, suprise they didn't find anything wrong. They also "cleared" the computer which I was very disserpointed about as I thought the computer had finally learnt its settings. I'd also forgotten to take off the Superchips program and replace it with the standard settings.
Galdly, it seems to be driving as is was before I got to the dealer. It still doesn't explain everything (like no warning lights) but if it works I'll be very happy.

Thanks for all your advice.