When I pull in the driveway or a parking space or sometimes up to a stoplight, the truck wiill start idling around 1000 to 1100 rpms and sounds like it is missing. Sometimes it will drop back to normal and the miss goes away and other times it just stays that way and the only way to get it back to normal is to shut it off and fire it right back up and it idles fine then. Anyone have any ideas? Its getting a little annoying