Hey guys. I need you help to confirm the part number for a 2009 LT 2.2L #2 O2 sensor (after the cat.)

Looking thru the information on this great forum, I believe I need ACDelco 213-3138.
When I visit RockAuto or Amazon, they both say this is the incorrect part for my car.

Also, if you can also identify the part number for the #1 O2 sensor - might as well do both on the 160K mile car!

I appreciate any assistance you guys can give!
Thanks!

 

Rockauto shows both up and downstream sensors. Up is #1 and down is #2.
https://www.rockauto.com/en/catalog/...2)+sensor,5132

 

GM12611127 #1 Which is ACDelco 213-4195
GM12578576 #2 Which is ACDelco 213-3138

Why would the #2 need replacing? If you have a code the most likely cause is a wire laying on the exhaust pipe. It only monitors the function of the Cat, The #1 does all the A/F work.

If you are thinking P0420 means the sensor is bad, you are 180 degrees wrong; it means it is doing it's job.

 

The code I am getting is P2270.

 

 

I really appreciate your help/expertise!
I read the following at the site;
"The most common fixes for this DTC seem to be either an exhaust air leak, a wiring problem with the sensor/wiring, or the sensor itself. If you replace the O2 sensor, buy an OEM one (manufacturer brand) for best results."

My plan was;

1. inspect the wiring first - if it appears intact and not touching the exhaust, then
2. Replace the O2 sensor.
3. If the code still appears - then I would tackle the Flex/Cat exhaust.

Please let me know if I am misinterpreting the cause and/or if there is something else I should check before getting the O2 sensor.

 

While you are inspecting things look at the flex pipe.

BTW; the sensors are NTK/NGK rebranded parts, you might save some money, I definitely would not shop at the GM parts department.

 

Thanks Don!

Local dealer wants $143 for the sensor.
Amazon ACDelco is $46 and the NGK is $55.

I hope to get to this over the weekend. Also changing out the plugs (with ACDelco) and air filter this weekend.