OK, I know it’s somewhere between the exhaust manifold and the tailpipe. 
I have a 1989 Camry wagon V6. Short of taking a chainsaw and dissecting the thing, I can’t make visual contact with anything remotely resembling an O2 sensor. My shop manual isn’t as specific as I’d like.
Anyone familiar enough with this car to tell me where to look? Or at least where Toyota sticks 'em?
In front of the cat convertor. … About the size of a spark plug, usually black/dark grey or copper in color with a wire coming out of the top.
Here’s a diagram of location
http://www.autoshop101.com/forms/h64.pdf
Don’t confuse it with the O1 sensor…
FYI I wouldn’t go poking at it until the car hasn’t been running in several hours, I want to say it doens’t even operate until it reaches 400 degrees, and I could be off on this, but I want to say that the temp of that exhaust pipe is about 600 degrees.