There are 2 oxygen sensors.
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 )
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My Chilton repair manual - engine wiring schematic shows ( 2 ) heated oxygen sensors for the 1993 Ford Explorer
There are 4 oxygen sensors on the 2001 ford f150 v6.
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 )
On the 4.0 L OHV engine - 2 oxygen sensors - and one sensor used as a catalyst monitor for catalytic converter efficiency mounted downstream of the converter On the 4.0 SOHC engine - 2 oxygen sensors and 2 catalyst monitors
Well, honey, a 1999 Ford Ranger with a 4.0 engine typically has two oxygen sensors. One is located before the catalytic converter (upstream sensor), and the other is after the catalytic converter (downstream sensor). So, there you have it, two sensors keeping an eye on that engine of yours.
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 )
My 1995 Ford Explorer with 4.0 L OHV has 2 oxygen sensors (Helpfull)
A 2001 Ford Explorer Sport , with the 4.0 liter Single Over Head Cam V6 engine should have ( 4 oxygen sensors )
Where and how many oxygen sensors are there on a 2010 fusion with a 3.0 v6 engine. Also when facing the front of the car which side of the engine is left and which is right