Renault Grand Scenic Help Please?!!!

[davidmog99]

Fully serviced 2005 1.6 petrol. Been stalling when cold, fine after a couple of minutes.
Today though, check emissions comes up on the dash, engine not running right at all, definitely not running all cylinders correctly, engine management light on.
My reason for posting on here was i remember a similar thread, and a guy who worked as a renault technician was really helpful, pointed out a common fault, and saved someone a lot of coin!