Can anyone tell me how many oxygen sensors are on a '96 blazer? Twilight Zone says there is 4 but their employees are about as bright as a box of rocks so I don't trust them anymore. I'm thinking there might be 3 but my buddy who is a tech says he thinks he remembers 4 of them on the '96 models. If there is 4, where would the other one be? I know one on each exhaust manifold and one after cat but the 4th one (if equipped)????????????????

There is four.

One on each of the header pipes just before the Y and one in front of the cat and one behind the cat.

I love my 1995, one in front and one behind the cat only.

Thats the way it should be! I hate this technology crap on newer vehicles. Thanks for your help

No problem.

There is four.

One on each of the header pipes just before the Y and one in front of the cat and one behind the cat.

I love my 1995, one in front and one behind the cat only.

Huh, maybe I have a mutant '95. I am pretty certain that it is pre-OBD-II, as that requires at least 2 O2 sensors. There is only one... A pre catalyst sensor, and that is it; on my rig that is. Makes me wonder if someone has been into that truck before I got there. You know, kind of like you are almost guaranteed to be the second guy crawling around inside the guts of the driver's side door. I wonder if anyone knows when the smog control changes happened over the evolution of the Blazer?

Huh, maybe I have a mutant '95. I am pretty certain that it is pre-OBD-II, as that requires at least 2 O2 sensors. There is only one... A pre catalyst sensor, and that is it; on my rig that is. Makes me wonder if someone has been into that truck before I got there. You know, kind of like you are almost guaranteed to be the second guy crawling around inside the guts of the driver's side door. I wonder if anyone knows when the smog control changes happened over the evolution of the Blazer?

He was asking about his 1996.

1996+ have four.