Holley Install Question
all of your other stuff is controlled by a body control module...completely separate from the engine/transmission control
piggy back is not an easy thing to do as you have to do it a very specific way to make it so the holley works properly...piggy back is not as simple as just splicing wires to both ECUs
many cannot be shared and you have to get all the grounds to the proper place and not share them between ecu's....





