i have a 2001 4.7 just installed a used engine, setting check engine light with P201 injector #1 firing improperly any help would be great.

 

unplug that injector us a noid light or connect yout test light between the 2 pins in the harness connector and start it the light should flash if it is you need an injector if not turn it off. then key on eng off test each conector pin one should have 12 volts the 12 volts is supplyed by the asd relay that should be good because your eng is running .
most likley is the pcm or a wiring ckt for that injector