On your Ford Explorer Sport , 4.0 EFI :
Bank 2 is the drivers side of the engine
Sensor 1 would be close to the engine ( it might even be in the outlet of the exhaust manifold ) BEFORE the exhaust enters the catalytic converter
Bank 2 is the drivers side of the engine in your Ford Explorer Sensor 2 is after the catalytic converter ( downstream )
its located in your MAF on the air intake ========================================================== The Mass Air Flow sensor is located between the engine air filter housing and the engine air intake tube on your 2004 Ford Explorer Sport Trac
The camshaft position sensor on the 1999 4.0 L OHV engine is located at the rear of the engine block on the top of the engine where the distributor was installed on earlier versions of this engine. (according to my Haynes repair manual)
On your 1998 Ford Explorer Sport : The mass air flow sensor is between your engine air filter and the big rubber engine air intake tube
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The 1998 Montero Sport crankshaft sensor will be located on the rear of the engine. The crankshaft sensor is on the inside of the rear engine cover.
Between the engine air filter housing and the big rubber engine air intake tube
On a 1991 Ford Explorer , 4.0 litre , OHV , V6 engine : I believe the oil pressure sending unit is on the drivers side of the engine , below the power steering pump
Bank 2 is the drivers side of the engine on your Ford Explorer Bank 2 / Sensor 1 is in the exhaust manifold or the exhaust pipe before the exhaust enters the catalytic converter
Bank 1 is the passenger side of the engine in a Ford Explorer Sensor 2 is in the exhaust after the catalytic converter ( downstream )
the Intake Air Temperature (IAT) sensor is located in the air cleaner to throttle body supply tube ( big rubber tube ) close to the engine throttle body.
On your 2002 Ford Explorer Sport Trac : Bank 1 is the passenger side of your 4.0 litre SOHC , V6 engine Sensor 1 would be close to the engine BEFORE the exhaust enters the catalytic converter