I've running real rich so I figured I'd replace it but I dont have one, before or after the cat. The exhaust is all stock. Its a 93 btw

 

its not on the down pipe off the headers? I can see mine in my 95 from the engine bay, and underneath.

 

Nope, unless I got my head up my a$$ and just not seein it (not likely). I was pretty shocked not to find one. So much for an easy fix to my rich problem.

 

follow your headers, straight off the head, all the way to your cat. if its not there, then its not there haha.

 

Check the wiring harness at the front of the engine by the fuel rail my o2 sensor harness beaks out of the engine harness and runs down to just above the axle and is clipped on a oil pan bolt is screwed into the exhaust pipe just under the header pipe. Mine is a 94 not sure if it helps ....

 

Ah ha, wow its way closer to the downpipe then I thought, I was lookin down by the cat. So my head was up my a$$ lol

 

hahaha! glad you found it, hope its not welded in like mine haha.

 

They are kinda tough to find. You may have 4 of them so keep looking farther down your pipes.