Error Code P0420

[GangstaCowboy]

Hello-
Check engine light came on last night so stopped by autozone to read the code. Showed code P0420 on the reader. Description shows Catalyst efficiency low-bank 1. From my understanding this is one of the O2 Sensors in the front of the cat. Any one had experience with this? Could the cat be bad? Thanks in advance.
T

 

[SunlitComet]

Left engine bank converter. Rear O2 sensor. This code basically says your converter for cyls. 1,3,5 and 7 is worn out and is no longer able to do its job. If the sensor is proved to not be at fault then converter assembly must be replaced. I also recommend replacing all 4 sensors if you do replace the converters.

 

[GangstaCowboy]

So left being driver or passenger side? I am going to try replacing the sensors this weekend. I did notice this morning that little retaining clip on one of the plugs is out, but it is on top of the transfer case or transmission so it was hard to see. I tried pushing the plugs in to see if they just wiggled loose but no change. Any recommendations on an good oem replacement cat? Or should I just go with whatever the muffler shop recommends?

 

[SunlitComet]

Driver side of engine but follow pipe back I think it switches sides below. Bosch sensors are always good. It can wipe the code on its own but it takes time to re- monitor the system to ensure everything is a go.

 

[GangstaCowboy]

Thanks for the information! Hopefully its the sensor as I recently got it inspected and they said the emissions were in good shape.