As far as I know, sensor 2 (O2 sensor number 2) is behind the catalytic converter.
Also known as the downstream O2 sensor.
It helps determine the efficiency of the catalytic converter.
Stuck signal can mean the O2 sensor is faulty
Or the wiring to the ECU (PCM) is open or shorted (to power or ground)
Can also be caused by exhaust leak or faulty fuel injectors or MAF sensor?

 

Stuck signal can mean the O2 sensor is faulty

And to clarify:

The FRONT O2 sensor ("Bank 1, Sensor 1") could be the culprit. That is what tells the ECU to adjust fuel ratio.
You need an OBDII reader to measure the real-time fuel trims. (A visual check of the wiring wouldn't hurt)

The Bank 2 sensor monitors the A-F ration and is doing its job.

 

Thanks for the help. I've been debating whether I should try to replace the sensor myself or just take it in. Seems like it can be one of several things. But as I have debated, the check engine light went off so it seems the problem has corrected itself. At least for now

 

Since it could be something other than the sensor, I'm of the view that it is probably best to have it professionally serviced with a service provider you know and trust.

What are the Possible Causes of the P2270 Code?
The PCM can get a biased lean signal from the post-catalytic oxygen sensor 2 because of these problems:

• Bad or failing oxygen sensor
• Exhaust leak
• Lean running condition
• Corroded or damaged wiring
• Failing PCM (rare) or PCM software in need of an update

source: https://www.carparts.com/blog/p2270...iasedstuck-lean-bank-1-sensor-2/#What_are_the_Possible_Causes_of_the_P2270_Code