Left battery disconnected for overnight. Same messages. I'll try the key on and off several times idea. Last message EFILive says after four retry's to communicate is "PCM is in an unknown state" Then EFILive says "disconnecting"

So did I mess up by mistakenly trying to flash the Operating System on a 1998 car? I know we can flash the Calibrations, but maybe not the Operating System. Glad it's not my daily driver.

Thank you for your inputs and advise; looking like I might need to take SinisterSS up on his offer to try and bench reflash my PCM.