Welcome to PF.

So when you say sluttering in traffic, is it when the car is idling? Or does it splutter after you have been in traffic then your pulling away??

I know its a different car but I had a problem with my cossie once,it would be fine say doing 50 60mph then when I got into traffic and the car sat for a while before pulling off the cossie would splutter/misfire cause the engine had got warmer. I fitted a water temp sensor which cured this fault.