O2 Sensor
 

My 2000 Audi A6 needs a new 02 Sensor, but I'm not sure which one to get.
I keep getting codes P1122 and P1140, I looked those up on this site and it says that it's for the Bank 2 Sensor 2..Does anyone know a site to buy the bank 2 sensor 2 at?

Bank: 1 - Passenger side // 2 - Driver's side
Sensor: 1 - Pre-cat (before the catalytic converter) // 2 - post cat (after the catalytic converter)

Hope this helps.

p1131 2000 audi a6
 

I have a 2000 audi a6 and the check engine light came on. Bank 2 sensor 1 resistance to high. what should I do to fix it? replace the upstream or downstream seasor??