When upgrading from a GEN3 to GEN4 ECU, the secondary set of fuel injectors are now controlled from a Big Drive which is enabled from the Boost connector on the main engine harness.
By moving the secondary set of injectors to the Big Drive, additional inputs and outputs were added to the Header 2 side of the ECU. You will not need a Big Drive on the primary set of fuel injectors if your current setup does not need one.
This kit only provides wiring harnesses only.
Parts Included: Fuel injector Y-Harness for connection to the main engine harness.