87 TBI Wiring

[Beyond]

Can anyone tell me where the exhaust sensor wire that goes into the drivers side exhaust manifold sensor originates at? I repaired my exhaust manifold this weekend and don't believe that sensor was hooked up. I looked all over the back of the block and around the firewall looking for a female plug to hook the sensor back into but haven't found one yet. Not sure if someone clipped it off somewhere or what. The engine must be running in "default mode" or something with that sensor unhooked and I think it's been that way since I got it a couple weeks ago. Also found that the temp sensor in the pass. head was broken off and not working, I'm kinda surprised the truck runs as good as it does 10mpg.