Wife said the CEL came on today. Pulled Codes P0138 HO2S Circuit High Voltage Sensor 2 and P2270 HO2S Signal Stuck Lean Sensor 2.
Any thoughts?
And which one is sensor 2? I've replaced the one closest to the motor a while back. Is sensor 2 the one further down under the car?

 

That’s correct the second one from the engine is the #2 O2 sensor

P0138 would indicate a faulty sensor or wiring issue

https://www.obd-codes.com/p0138

P2270 points to other probable causes like an exhaust leak

https://www.obd-codes.com/p2270

so be aware a new sensor might not resolve your issues

 

Probably need a new #2 sensor. That is the one after the cat.

P0138 This is one of those descriptors that does not mean anything like what it sounds. What it really means is that the sensor is stuck in the test for rich.
P2270 actually means the sensor is not able to read a high enough voltage.

 

Thanks Don. I'll get one in and see what happens.
Figured #2 was after the cat, but wanted to make sure.