2004 Tahoe, 5.3L P0131 code and readings from obdII

Im a home mechanic with very little knowledge of computerized engines. Engine light came on, engine running rough. Checked fault codes with a Torque Lite reader. Initially logged a P0300 and P0171 code. Cleaned throttle body and MAF sensor. Cleared codes. After 30 miles logged 4 codes, p0300, p0171, p0131, p1133. Read up on forums and cleared codes again and this time was monitoring systems while driving. Went 10 miles only code P0131. Cleared again and this time drive 60 miles before code p0131, no other logged or pending codes. Code reader is limited on function I can view, no LTFT available but this is the results during drive cycle.
MAF idle 8.8 up to 43.8 on acceleration, 26 to 34 on freeway steady speed 60 to 73 mph
STFT started at 2.2 then would go to 6 to 7 on acceleration, when code tripped it went to 53.3 and stayed there for 10 to 20 miles then went to zero and stayed there.
02 upstream driver side started at .1v went to .2 then drops to zero and stays there.
02 upstream passenger side started at .1 went to .7 on highest read

I just bought wife new car to replace this Tahoe. Its in very good condition and has 176k. I want to sell it but want to have this issue resolved for new owner.

From my very limited knowledge and research it seems that the drivers side O2 needs replaced.

Am I on the right track ?

I'd say you are on the right track. Before you can the condemn the O2 sensor, I suggest adding some propane into the intake. If the the O2 sensor is good, and telling you the truth that you have a LEAN condition, it should react to the propane and go rich. Also, check your signal circuit integrity. If you dis-connect the sensor, you should see a bias voltage of 450 mV.

I'll do that and post results.