97 Explorer - Check Engine P0153 code

Check engine light came on & had it read at Autozone. The P0153 code indicates O2 Sensor CKT slow response, bank 2, sensor 1. Also getting a Manufacturer Code 1151, Fuel/Air Metering, lack of HO2/S21 switch, sensor indicates lean. Was told most likely an O2 sensor needs to be replaced. Was told there are 4 sensors, 1 before & 1 after each of the catalytic converters. Where is bank 2, sensor 1 & is this pointing at 1 of these 4 sensors?

I have same problem on same year Explorer. Did you ever find which sensor is bank 2 sensor 1? Did you replace it yourself? If yes, any words of widom to share?

Thanks

Bank #1 is always the same side as spark plug #1, the passenger side. Sensor #1 is the engine side, Sensor #2 is after the cat. A box end wrench will fit over the connector if you break off the locking tab. If it really is bad, no reason not to cut the wire. An open end wrench will just strip. Some auto part stores have the socket on loan a tool. It will take a good hit of a hammer on a wrench to get it off.

Thanks for the update.

Does the new sensor have to be torqued or just hand tightened?