I scanned my car and the reading is sayin O2 sensor bank 2 is bad, which O2 sensor is that?

 

the one by cat

 

Thanks

 

If it said B2S2, sure. Bank 2 could also mean an upstream.

 

Bank 2 is the one in the front near the radiator (cyl 2,4,6)
Bank 1, sensor 1 is the one near the firewall/oil filter (cyl 1,3,5)
Bank 1, sensor 2 is the one near the cat

http://www.jatan.net/02Sensor1.jpg
This pic is for a cali spec, but you get the bank/sensor number idea - fed spec will look like this: http://www.courtesyparts.com/A32_O2-sensors.html