Bank 2 sensor 1 location
 

I have an engine code of PO154 O2 sensor CKT No Activity (Bank 2 Sensor 1). Can anyone tell me where this sensor is located. I believe that I read somewhere that there are 4 o2 sensors. Is this correct?

Forgot to mention
 

I am sorry I forgot to mention that it is a 1999 S80 Turbo.

Thanks

Bank 2 is on the left side of engine, driver side. Sensor 1 is before the catalytic converter.

Thank you for your response. Do you know if there are actually 4 of the O2 sensors? If there is more than one do you know if they are all the same part number.

You have four sensors.
I'm not sure if the front two are the same, but the rear two are the same. But the front are different from the rears.

Thank you so much for the information. You have been a great help.