More....

  My assumption for connecting the single wire Bosch sensor like this, with
just the one signal wire attached back to the ECU is that the ECU most
likely has a common ground that allows signals to be sent to it without
having another ground wire going all the way back to the source...

  If these single wire sensors work with just one wire in most vehicles
that use them,....well...    But I may be wrong and my particular ECU may
require an individual ground for the O2 sensor....I just don't know and I
am unable to follow a complex wiring diagram to suss out the answer...