In the mornings, after the truck has been sitting all night, it has a hard time idling and runs extremely rough for the first 10 seconds. I am not showing any codes on the PCM and it doesn't matter on the outside temp. I was thinking that it was a fuel pressure issue, but I have plenty of pressure on the gauge mounted on the fuel rail. I was wondering if it could be a bad Map sensor or some other type or sensor on the engine? Any Ideas?