Went to the local auto parts store to get a new oxygen sensor for my 93 bronco 5.8. Anyways they say there is 2, one ahead of the cat and one behind it. I was just under the truck and replaced the one before the cat at the headpipe but i dont see another. All i see after the cat on the exaust pipe is a pipe that runs up behind the motor that looks like it goes to the EGR or somewhere else. The exaust looks all stock and not modified in anyway. Anyone have an idea on this? should there be 2? or is the auto parts store wrong?

 

Only one O2 on that truck... parts store guys never get this right.

 

Ugh! Parts counter flunkies. If it doesn't show up in the computer in front of them they know nothing! The EEC-IV system used one. The OBD-II system used three.

 

I'll add that there are some OBD-1 trucks with two sensors but they are California only models and both sensors are at the front, there is still no rear sensor.

 

Just got back from the store retuning the other sensor. When i told him there was no rear sensor he just looked puzzled. I told him that i researched it online and the consensus was no rear sensor. He just quietly returned my money.

 

I wouldn't worry too much about it. I had an AZ counter kid tell me the Bronco was never equipped with a 5.0 (302) in 1992! Even went so far as to tell me the Bronco wasn't made after 1990! I led the kid outside, opened the door so he could read the date of manufacture while his manager just sat back and snickered. When we got back inside, the manager had the part I requested already pulled, handed the kid a broom and told him when he decided to be less cocky and listen to his customers he could go back to the counter.