cylinder #6 misfires but only when the car is heated up and only does it for about five mins (check engine light flashes) and then it stops and the car runs fine.. any clue what could cause it?.. i've changed the spark plug and wire

 

You may want to check the coil.

 

coil was replaced as well

 

Have a ford dealer diagnose the check engine light....i believe they do it free but not positive