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
There are 2 oxygen sensors.
yes
My 1995 Ford Explorer has ( 2 ) and depending on the year anywhere from ( 1 to 4 ) and it also depends if you have the 4.0 liter OHV or SOHC engine
On a 1998 Ford Explorer XLT : With the 4.0 liter SOHC V6 engine ( 4 oxygen sensors , the 2 closest to the engine are used for adjusting the fuel ratio and the other 2 are catalyst monitors There are also ( 4 oxygen sensors if you have the 5.0 liter V8 engine )
No , the 4.0 L V6 engine in a 1996 Ford Explorer is an OHV not a SOHC
On a 1998 Ford Explorer Sport : If it has the 4.0 litre EFI engine ( which is an over head valve / pushrod design engine / the 8th character of the VIN is an " X " ) there are ( 3 oxygen sensors ) If it has the 4.0 litre SOHC engine ( the 8th character of the VIN is an " E " ) there are ( 4 oxygen sensors )
For a 2003 Ford Explorer : There were two engine sizes offered from the factory ( the 4.0 liter SOHC , V6 engine , and the 4.6 liter SOHC , V8 engine )
The 4.0 liter OHV engine has ( 3 ) The 4.0 liter SOHC engine has ( 4 ) The front ( 2 ) oxygen sensors are used in the adjustment of the engine air / fuel ratio
Either the 4.0 liter SOHC - V6 engine or the 4.6 liter SOHC - V8 engine
In a 2002 Ford Explorer 4 door , either the 4.0 liter SOHC - V6 engine , or the 4.6 liter SOHC - V8 engine
The Ford 4.0 liter SOHC engine has ( 3 ) timing CHAINS
No , same part number - Motorcraft FL820S 2002 Ford Explorer - 4.0 L - SOHC - V6 engine ( FL820S ) 2003 Ford Explorer - 4.0 L - SOHC - V6 engine ( FL820S ) 2002 Ford Explorer - 4.6 L - V8 engine ( FL820S ) 2003 Ford Explorer - 4.6 L - V8 engine ( FL820S ) according to the 2002 and 2003 Ford Explorer owners manuals