Oxygen sensor 1997 Jimmy

Where are both of the Oxygen sensors located on a 97 Jimmy?

On my 97 jimmy there are 4 one on the left bank around the second plug, #2 is about 2feet down the exhaust pipe from that #3 is right before the catalitic converter and #4 is right after the converter.
They are around $50 each,If you change them yourself use plenty of Blaster, or wd40.They are not bad to change I used a cresent wrench to change 3 of mine.