There are two, located in the Y-pipe. They are just down from the manifolds. The connector plugs are located above the bellhousing behind the cylinder heads.
That would depend on what year of Ford Explorer and which engine you have ( my 1995 Ford Explorer with the 4.0 liter OHV , V6 engine has ( 2 oxygen sensors )
there are 4 o2 sensors
There are 2 oxygen sensors.
The O2 sensor on any vechicle will be located on the exhaust manifold.
A 2001 Ford Explorer Sport , with the 4.0 liter Single Over Head Cam V6 engine should have ( 4 oxygen sensors )
I can assure you that the O2 sensors will not prevent the enigne from starting, even if they are disconnected or removed. Something else is the culprit.
( two ) I believe they are in the outlets of the two exhaust manifolds
Don't know what your original reading was, but the O2 sensors before the cats moniter how the engine is running and the O2 sensors after the cats moniter how the cats are performing.
how many o2 sensors on a ford e350 van 2003
i wanna say four two before the cat and two after it.
4 ======================================================= The above answer is correct if you have the 5.0 liter V8 engine in your 1996 Ford Explorer , but if you have the 4.0 liter EFI , V6 engine ( VIN " X " ) there are ( 3 oxygen sensors )
If it's like a 1991 Ford Explorer ( with the 4.0 liter V6 engine ) It has ( 1 ) oxygen sensor