I've spent more time on this harness than I care to admit. I think I have it the way I want it after the 4th revision.
Basically, this harness plugs into the power tap connector on the Holley harness. It's got ignition 12v, chassis ground, sensor 5v, and sensor ground. I made a pass-through connector for the main power tap, so I can plugin with another metripack connector if I need to add any more sensors in the future. This harness is for the dome pressure sensor in the wastegate, and flex fuel sensor. 4 wires go into the car, Flex signal, Dome pressure, ignition 12v, and the chassis ground.