I have 2 codes, both are 2626, but one is says pending.
as per bentley; O2 sensor pumping current circuit open(bank1 sensor 1)

My question is, since the vehicle has 2 O2 sensors, and I have 2 identical codes, does this mean both sensors are creating a fault or 1 sensor is sending 2 error codes( if that even makes any sense)

 

That would be the one before the cat.

 

Since I had the exact same issue, try to simply unplug and re-plug the O2 sensor. My problem was probably the connection. A year has passed since then and I din't get the error again. I read in another forum that the culprit is a resistor built-in to the sensor, which is used for calibration purposes.

If your problem persists, then you are looking at a new O2 sensor, which can be pricey but easy to install.

 

fixed, upstream 02 sensor