Just after the air filter, toward the engine.
My Chilton repair manual - engine wiring schematic shows ( 2 ) heated oxygen sensors for the 1993 Ford Explorer
two oxygen sensors for air / fuel ratio (and another two oxygen sensors that are called catalyst monitors installed downstream )
Most oxygen sensors are heated oxygen sensors.
All O2 sensors (AKA Air/Fuel sensors) are threaded into the exhaust system. Some before the catalytic converter (upstream) and some after the catalytic converter (downstream).
According to the engine wiring schematic in my Chilton book : For a 1999 Ford Ranger , 4.0 liter EFI , V6 engine : ( there are 3 oxygen sensors )
an o2 sensor is the same as an oxygen sensor. vehicles can have up to 4
The 02 sensors are in the exhaust pipes but don't know about the updraft sensors.
exactly where is of 02 oxigen sensor the ford windstar 2003
Where is the shiftseleniod con a 02 ford focus
before and after the catylitic converter.
There are several 02 sensors in that vehicle depending on which engine you have. They are all threaded into the exhaust system at various points.
According to my Haynes repair manual : For a 1997 Ford Explorer , 4.0 liter Single Over Head Cam , V6 engine : The engine wiring schematic shows ( 4 ) oxygen sensors