DTC P2270 & P2271

[358429]

About once or twice a week (w/ daily driving) the ECM throws P2270 or P2271.

 

DTC P2270

HO2S Signal Stuck Lean Bank 1 Sensor 2

DTC P2271

HO2S Signal Stuck Rich Bank 1 Sensor 2

 

Is it reasonable to suspect that the sensor has failed because it is switching between lean and rich?

 

Where is Bank 1 Sensor 2 located?

[txab]

Driver's side, post cat sensor

[358429]

Is it reasonable to suspect that the sensor has failed because it is switching between lean and rich?

 

I would think there were some other issue, like a leak or something to cause it to run rich it would only display rich or lean and the code would return immediately after clearing, similar to when I had an issue with my evap vent. After clearing the code, the code does not immediately return. Sometimes, I will go several weeks between codes.

[Duelin]

The only common thing between the 2 codes is a failing O2 sensor. One code is for a lean reading caused by a bad sensor or an air leak near the sensor. The second code is for a rich mixture cause by a failing sensor or a leaking injector or leaking regulator. Check the connection real close for corrosion on the terminals.

[358429]

Thanks for confirming my thinking and suggesting checking for corrosion.

[358429]

I wasn't certain which p/n was correct, so I called AC Delco and they gave me the correct part number. Ordered from Amazon and with the help of PB Blaster, heat and elbow grease, I got the old one out and the new one in with little trouble. The code has not returned in about 5 drive cycles.

 

Also purchased the Airaid MIT for my truck.

 

Thanks again for everyone's input and assistance.

 

 

ACDelco 213-4229