Hi,
My saxo vtr is suffering similar problems, cutting out at lights, traffic, cold -revs drop then shoot up.
From what I can gather it's something to do with the air inlet manifold sensor.It's telling the throttle control that there's enough oxygen going to the engine but its not.
I've got my own question up regarding this issue and waiting for confirmation before I set about my car with a blow torch.
If you do get any info I'll be grateful if you could forward it on to me. But what ever you do dont let any garage change your ecu/ temp sensor / idle control , as its not the ecu that has the fault, and it costs an arm and a leg.
amo, January 2007