The Zook Performance Products G16b ECU Patch Lead is the idea product when wiring standalone or Pigi-back ECU to the standard 22 & 26 pin plugs wiring harness.
 
There is no need to cut or splice the factory wiring. This lead is essentially an "extension" harness. So simply modify this harness to work with your chosen ECU application and install method.
 
Making the wiring completely reversable.