Can anyone please tell me which cat's 02 sensor is the bad one? The drivers side or the passenger side?

I have HFC's, and called Kinetix, had to rule out the cat itself, because it's odd only one is the bad one, so it has to be an 02 sensor (which is also a bit weird that is would fail now, only at 22k miles).

 

looks like bank 2, which is driver side

 

Yes, I was told "bank 2" but I have no idea what that means.
Nissan did not tell me and auto stores said bank 2 means behind the cats.

 

on post 04s there are 2 sensors - 1 and 2... sensor 1 is at the exhaust manifold (headers), sensor 2 is downstream at the cats... bank 1 (for either) is on the passenger side, bank 2 is the driver side... sensor 1 is a wideband sensor and is more critical than sensor 2 (narrow band) - I don ‘t want to go into details, but bottom line is if your code is for sensor 2 its not a hyper-sensitive issue. If its sensor 1 you need to replace.

 

Ok, so Bank2 is on the driver's side.
But which sensor is it? The one at the header or the cat?
It says "TW" on the printout, I am assuming that means "two" so it would be the one on the cat?

 

if TW means two, then yes its the one on the cat

 

^I was just guessing on the "TW".

Nissan wanted $95.00 to check it again and see what sensor is the bad one.
I said **** that, going tonight to a friends to use his scanner...