You're not going to believe this.
Put the old sensor back in to plug up the hole in the exhaust. I plugged the connector back in so it wouldn't fall on the headers.
Turned ignition on, turned on controller switch (which I added to relay) & the damn thing is working!!! The LED is flashing in the right sequence & goes solid in the normal time frame.
The only thing I did was clean the carbon off the old sensor with Brake Kleen.
It worked 2 times in a row. Reconnected his serial port to check calibration, reset & it rebooted normally.
This could only happen to a controls engineer (LOL). I have no explanation.
Since I have TS configured for NB & never tested it, will give it a try tomorrow or Sunday. It looks like that cold front won't be moving through until then.