Hi

I have a 2.2 petrol vectra c and each time you start it up it'll stall, it tries to fight this but in the end it stalls, my mate reckons it is misfiring. Once started and going it runs fine this just happens on startup. I put on a diagnostic tester and there are no fault codes being stalled, i've changed spark plugs and cleaned EGR valve but the problem is still persisting!!! Can anybody help me please?

John