Holley efi with 4l80
email holley tech for a full size color png file of the trans harness and use a vom to tone it out. you probably have some wires to the pressure switch manifold changed around. the holley stuff is awesome but the harnesses are .... less than stellar
from there we start diagnosing possible issues with the trans itself. holley gets its PRNDL signals from the pressure switch. if there's any pressure problems in the valve body it'll read funky





