how do you figure out which o2 sensor is bad

Question

I have a code of P2626 up, how do I know which o2 sensor is faulty.

Answer 1

P2626 this is for bank 1 sensor 1, Bank 1 is where cylinder 1 is located on that side, the Sensor 1 is the upstream 02 sensor this is before the catalytic convertor, Bank 1 one these engine get to know that side, there always a problem on that side.