Originally Posted by upallnight

You could be getting the lean codes because the DME is shutting down the injectors to prevent you from destroying the trans with aggressive driving, however as you continue to drive the car, the DME is still monitoring the engine and with the injector(s) off you now have a "Lean" condition.

Don't drive aggressively and see if you still get the injector shutoff. From your previous video it looks like if you didn't drive aggressively the truck accelerated normal.

Edit:

When you replaced the fuel rail, did you replace all the o-rings on the injectors? Disturbing the old o-rings could also be a source of a vacuum leak. Any time I pull a fuel rail I would replace all the o-rings and put a little oil on the o-rings so they go back into the intake manifold easily.