P2271
What fuse is involved in that system?
In my wife's old car, there was a short in the wiring that caused the O2 sensor to look like it failed.
that in turn also took out a fuse.
Once I fixed the short, I still didn't have power.
It has been a looong time, but I recall that fuse not being the easiest thing to find.
Happen to have a volt meter that can check ohms? and even better yet one that sends out the beep signal when it shows 0 resistance?
Go through every single fuse, start with the ones that sound correct.
engine bay fuse block to start, most likely there.
If fuses check out,
I would probably start by checking for voltage going to that circuit with the O2 disconnected.
If the issue is just on one side, check the "Good known" side for a reference.
Do an ohms check with the power off to look for a short circuit on the heated sensor side.
Also look over the plug on that "new" o2 carefully.
And if that's the only code for the bank 1 side, then also try flipping the sensors around to see if the code follows the sensor.
If not wiring or a fuse,
Depending on where you bought the sensor, look at it with suspect.
P2271 - searching on that, I see it mentioning an issue with the heater circuit.
And the sensor not switching from rich to lean (or something close to that).
The Powertrain Control Module (PCM) detects the Downstream O2 sensor does not transition from a rich to lean condition within a specific time during a DFSO event. Default action this DTC the MIL light illuminate.
www.obd2-code.com