87 trooper O2 sensor?

The manual I have for this car discusses the O2 sensor but does not show a diagram of it nor does it specify where it is. Can someone tell me
where it is, or at least what part it is on, so I can find it and identify it? (it's not currently problematic, but i have this car torn apart now anyway and I may as well figure out where everything is that i don't already know about). TIA, k wallace
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.