Stalling S40

I have a problem with an S40 1.6 stalling when coming up to a junction when the engine is cold. I understand a garage has cleaned out the idle control valve which used to fix this problem but it has not worked this time. A replacement idle valve was fitted but it made no difference. Does anyone have any idea's what the problem is likely to be ? Are there any common problems causing stalling or poor idling ? Thanks

Thanks for the pointers. Yeah TPS and vacume leaks would be good to check.

Had a quick look today. I think I can hear a small airleak from the top of the engine which would explain the problem. Was difficult to locate when I removed the plastic cover though. When I turned the ignition on I could see an engine fault light. What does it look like ? What is it next to ? I saw a SERVICE light and maybe a CAT/emmissions light

Does anyone know what the ecu light looks like ? Thanks