Where is ignition coil on 1999 4.6 ford expedition?

The ignition coils on a 1999 Ford Expedition 4.6L are located on top of the spark plugs. They're not a single unit like some cars; instead, each cylinder has its own coil directly above the corresponding spark plug. You'll need to remove the plastic engine cover (if equipped) to see them clearly. They'll be relatively small, black cylindrical components.