Which one is bank 1 sensor 2

I have a 1998 XJ getting OBDII codes

P0138
O2 Sensor circuit high voltage (bank 1 sensor 2)

P0141
O2 Sensor Heater Circuit (bank 1 sensor 2)

Which sensor do I need to replace upstream or downstream?

:confused:

The one after/on the cat

Sent from my nerdy smartphone

In rockauto.com there is two choices, which one OBD refer as bank 1 sensor 2

NTK Part # 23151 Upstream; 1; 2; NTK is the OE Mfg $35.79
NTK Part # 23099 Downstream; 2; NTK is the OE Mfg $35.99

Downstream right?

Yeah it will be the downstream one