Here's the history of the 2004 Explorer with 4.0 V-6 problem:

Wedneday: engine turns over but will not start

Thursday: Code reader shows throttle position sensor 4 times, ordered one.
Wrench light and service engine lights on.

Saturday: Installed new complete throttle actuator assembly

Turns over, will not start.
Disconnect battery & reconnect, will not start.
Unplug MAP sensor, now it starts, but will not rev up.
Turn on key, push pedal to floor, slowly release, still no rev up.
Buy and install new MAP sensor but will not rev up.
Repeat pushing pedal to the floor, and releasing slowly.
Code still shows throttle position sensor. Try clearing codes and
re-reading code, still shows throttle position sensor.
Wrench and service engine lights still on.
Try calibrating throttle few more times.

End of daylight Saturday: out of ideas. Looking for more. Could it be the actual foot pedal control?

Thanks for reading, help appreciated. "Moma" wants her truck back ;-)

Thanks, Bill

 

Please include the actual code numbers that are stored.

Since unplugging the MAF seems to help, I'd suggest you check for pretty significant vacuum leaks. Are you absolutely certain that you have all the intake air tubing correctly installed from the MAF to the throttle body?

-Rod