Originally Posted by Penn999
No, its not just on a cold start. I believe when he is saying a "cold" start he is meaning when the engine is completely cold. As in....has been able to sit for several hours and totally cool off. It is just more evident in the colder weather.
Well "so far" i've had two cold starts and no rough idle after pluggin the exhaust flapper valve back in....
I'm gonna keep testing my theory, but i think the exhaust flapper valve is something that our cars need for a smooth idle at startup...