So i've got the one on the passenger side rear top of the plenum connected. It separates from the efi part of the harness before coil and connectors separate from it. I also have the one the driver's side hooked up, the one next to IAC that actually has 2 wires bolted in one location. The one you mentioned from fuel rail to the lower plenum I guess would be the missing one. What worries me that since I didn't notice it when installing the plenum, it might be tucked in somewhere underneath it now... But would not having that ground connected still allow the injectors to click when I rotate the CAS? Or would it affect the fuel delivery system in any other ways? Maybe it is just an extra/redundant ground? Because the injectors click. I will check on the chip.