Don't waste your money unless you have determined they are bad. Check the connections, scope the sensors if you can, and THEN replace them. Or if you want to skip all the diagnosis and replace them you may solve your problem when you plug in your new sensors all the way

 

If you are not ready to replace them, check the passenger side front sensor. The wires have a habit of laying on the cat. No activity means the wires are cut or it is unplugged. Might be that it is just totally fried too. Bank2 sensore one I think is for RH front. I was checking my truck and found the wire laying over on the cat. Check this first...

If you have 127K on it, you will get better performance out of your truck if you replace all 4. If you have the $$ and they haven't been changed, change them all.

 

Is there any way you can tell if they have been replaced?

 

Thought you might have reciepts.