I have a 2005 F-150 5.4L that was throwing a misfire code. After having a mechanic run a diagnostic on it, got the truck home and noticed the ignition coil was not placed back in the cylinder properly. After removing the coil, the spark plug was stuck in the bottom of the coil and came out with the coil. Looking at the spark plug, the electrode and some of the spark plug is missing. Several questions, where could this piece be? Can this piece of spark plug get down inside the engine block? We have taken an inspection scope camera and did not find the piece in the cylinder. If the piece is not located, can we safely place the new spark plug in without causing damage to the cylinder, piston or piston head?