Doing a Tune-Up on my old F150 this weekend and I'm just wondering how many O2 sensors it has. I thought it had two, but I can only seem to locate one just behind the Cat on the passenger side. Is that the only one, or am I just not looking hard enough?

Edit: It's a 1995 with a 5.0.

 

I don't know, but go to an auto parts store and ask. They should be able to tell on the computer.

My '97 EB Expy has 3 O2 sensors.

 

Additional info.

1 O2 sensor coming off of each side of the manifolds (that's 2) and the third is after the Catalytic converter.

 

There are four. one just behind each manifold and one behind each cat.

 

There are 4 have fun changing them....a case of beer helps.

 

FWIW, the 95 V-engine should have TWO sensors. One on each exhaust manifold. They are used to monitor fuel trim.

All 96 - on V-engines should have FOUR sensors.

FWIW, there is no benefit in replacing the downstream sensors unless they have specifically failed.

Steve

 

There are 4 O2 sensors. 2 on the left and 2 on the right side,with 1 on each side before,and 1 each side after the cats.
There around $50 or so each,and the ones before the cats can be a pain.
there is really no need to change 'em unless you have a check engine code going on for it.Then only replace the bad one.