94 f150 5.0 auto trans. When I start the truck it will idle just fine for a moment then the check engine light starts flashing the truck idles really high and then the light stops flashing and it idles back down and sometimes dies. But will start right back up with engine light on no flashing and run just fine. Sometimes it doesnt do it at start up it will wait till im down the road a few blocks and start cutting out almost die until the light comes on then its just fine as long as the light is on. What could be causeing this problem?