I know what this
dtc is, how to fix it, and possibly how to fool the PCM, but I am not interested in doing any of these. If I continue driving in this conditio, can I do any harm to my vehicle?

 

It can possibly damage the exhaust, cat and the engine. Depends on what is the main cause and how badly is it? Misfiring? Excessive fuel?

 

Running very smooth averaging 22,5 mpg @ 75-80mph. Might be off a little. Good power, smooth shifts, no odors or other codes.

 

Sounds like you do not have much to worry about

 

Just completed 2M mile trip with no other problems, but the code comes back soon after clearing it. Oil consumption was minimal. Anyone know if I am running in “limp Home” mode, or is the O2 sensor #1 still controlling mixture?