but like auto zone orders one and its flashed
and O'rellys flashes the PCM with out the car there
is the BCM have to be done a different way then the
PCM?

a factory might have different ways with a connector right to the pcm connection. dont know. before 95-96 you could transfer your chip to the other pcm, but after that i think you have to have either programed by a tech 2, in your car. some late 90'* ones may work before they went to bcm and security in the bcm/pcm. all those need is crank relearn which some other scanners can do.