Don't know about the 4-cyl for certain, but the diagram of the 4-Cyl in my Haynes repair manual shows one exhaust manifold, so I'm guessing there would be one. The best way to determine this would be to examine the exhaust manifold. On my truck, this is easiest from below the car On my '94 6-Cyl there are two. They are located on the small end of the exhaust manifold. They can be most easily seen from underneath the truck near the transmission where the manifold connects to the exhaust. They look like a silver tube about 3" long sticking out of the manifold and have a 4 connector cable coming from the end.
there should be 3/1 on the left header then 2 going back
Two, one upstream (before cat) and one downstream (after cat).
I have a 1996 cadillac deville concours, an it has 4 oxygen sensors
Firing order for 1996 Ranger 4-cylinder engine is 1-3-4-2.
All oxygen sensors are threaded into the exhaust system.
The oxygen sensors on a 1996 Chrysler Town and Country are screwed into the exhaust system behind the engine.
The front engine cylinder
two
two
4
3
In a 1996 Ford Ranger : The factory available engines were : 2.3 liter four cylinder ( 4 cylinder ) 3.0 and 4.0 liter V6 engines which are ( 6 cylinders )