2006 Ford Expedition - sudden loud pop/bang no power. Then intermittent power at 3000rpms not shifting?

Heard a loud pop/bang and suddenly no power when driving… Turned the car off and was 'going' but shifting horribly and intermittently. No check engine lights on dash. Turned off overdrive and power was better but only beyond 3000rpms… Any thoughts?

Transmission is blown most likely. Check the transmission fluid dispstick and check the level. Empty means the transmission has blown.

A problem may be caused by a spark plug that has blown out of the cylinder head
I was driving to work this morning and was exiting the highway and heard a loud pop and my truck (2002 F150 5.4L) started to shake and lose power. I coasted into a parking lot (which happened to be a Chevy dealer). I parked the truck. I popped the hood and found that the number 3 plug had blown out and that the coil pack was broken as well. My fix was, I bought a spark plug heli-coil tool and drilled and tapped the hole, replaced the plug and coil pack

If you want to fix the vehicle go to the dealer and quit messing around with DIYers guesses that won't do anything but entertain mechanics reading and laughing at the dumb suggestions.