Hi All, Considering replacing the rear oxygen sensors on my 14 Silverado with the 5.3 flex.
Looking up GM part numbers (#126547188) mentions it needs to be programmed?
I don't understand that. Can anyone assist me on this please?

Thank You

 

What is your reason for replacing? Is it bad or do you just feel like replacing it

 

More of a preventive measure

 

There's not a whole lot to "prevent".

All those do, is allow the ECM to tell how well the catalytic converter is working. If they go bad they set a code and the Check Engine Light lights. If it's not lit they're not bad. I'd leave em alone in that case. It's usually best not to poke the bear... if it ain't broke, fix it until it is, as they say.

 

So long as the rear O2s consistently report under .3V whenever Power Enrichment is NOT in effect, the rear O2s don't need replacing.