XLT 4X4 5.4L/ Several months ago, engine began intermittently running rough and chugging like it was not getting enough fuel. Lasts about 5 seconds, never dies, will correct itself on its own, or increase rpm corrects it. No codes. Finally got a check engine light and code of a bad cam sensor. Replaced it but problem still exists. After short trip of 10 miles and speed about 40, this only occurs when I pull up sloped driveway and am idling for a minute or two, or after highway speeds for an hour or more, it will occur when slowed or stopped. Have replaced fuel filter and plug wires, also. About to do plugs. Have searched here and MANY forums, found similar problems, but those all resulted in engine dying and not re-starting. Have driven vehicle with analyzer on for a 6 hr road trip, engine problem occurred at least 4 or 5 times during trip - no codes. Any suggestions on what to look for now?