Jeep Repair: Oxygen Sensors, oxygen sensors, jeep wrangler

Question
I have a 2000 Jeep Wrangler 4.0 Liter 6 cyl. the code is a bad sensor in bank 2 sensor 1. There are 4 sensors, which one is it?

Answer
upstream  sense u have a 4.0 both pipes come to a point  i cant tell u for sure which one with out using a scanner to locate it. U can unplug one of them and see if u get the same code for it ya know.  bank 2 sensor one  open  that sorta deal  and u know u have the right one.