oxygen sensor help please...

[crum2243]

I have the code PO141 - O2 Sensor B1 - S2 - I have a 96 Explorer with the V6

I need to replace this oxygen sensor after researching this site. I find out that this would be the passenger side sensor farthest from the manifold (S1 being closest to the mainfold)

After checking my Chilton it says that the 96 had 4 oxygen sensors but after crawling around under the truck today I can find only 3. One on each manifold coming out of the engine and one on the exhaust just after the cat converter.

Autozone website shows 4 sensors but I can't find the 4th.

Where are they all located and which one is the B1-S2?

Also Autozone shows them all to be the same type but it looks like the one behind the cat is different than the two off the manifolds.

Thanks for any help.

 

[Rhett]

Do not take your Chilton's as gospel. There are variations in the numbers of O2S on a lot of years of Explorers. -- and Chiltons or Haynes are pretty good, but not expert in their knowledge of a particular vehicle. For example, most 93 Explorers have 2 O2 sensors; but some only have 1. A Haynes or Chiltons manual will say 2 O2S for a 93 Explorer.

 

[Robert]

Your OHV V6 only has 3 O2 sensors. The V8 and the SOHC that was introduced in '97 have 4.

 

[crum2243]

Thanks for your help - this appears to be the case.

After crawling around some more under the truck and having a friend look at it I am convinced there are 3 sensors - one on each manifold and one after the cat on the exhaust.