Not sure what USB to serial I have. It's the one that came with my Tuner. Is the plug on the side of the Tuner (G321) used? I can't find anything about it in the User's Guide. And yes I would like an off-board cable to flash a PCM outside the car. I just need to know what wires go to what pins on the Tuner. There's a bundle of wires coming out of the PCM and only 15 going into the Tuner. Or only 4 + ground with a USB coming from the computer. I can make my own IF I had the wiring diagram. Or how much is a cable from you for a 04+ and one for a 97-03 also? Thanks