The 4 YELLOW wires with black stripes will tap into the coil pack outputs at pins 42,43, 57, and 72 on the c1551E plug (the topmost plug on the ECU). It doesn’t matter which of the YELLOW wires go to which output, only that they each go to their own output The GREEN wire will … Continue reading Aux Fuel Wiring Diagram for 2015-2017 Mustang EcoBoost