Bank 1 is the passenger side of the engine Sensor 1 is in the exhaust close to the engine before the exhaust goes through the catalytic converter Sensor 2 is after the exhaust has gone through the catalytic converter ( downstream )
Bank 2 is the drivers side of the engine in your Ford Explorer ( V6 or V8 ) Sensor 1 would be close to the engine before the exhaust enters the catalytic converter ( upstream sensor )
On a 1999 Ford Explorer : Bank 1 is the passenger side of the engine ( 4.0 EFI / 4.0 SOHC / 5.0 V8 )
On a 2003 Ford Explorer , 4.0 liter SOHC , V6 engine : Bank 2 is the drivers side of the engine Sensor 1 would be close to the engine BEFORE the exhaust enters the catalytic converter ( used with adjusting fuel ratio ) Sensor 2 would be AFTER the exhaust exits the cat. ( also called a catalyst monitor )
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
On a 1997 Ford Explorer XLT : Bank 1 is the passenger side of the engine ( 4.0 liter SOHC , V6 , and 5.0 liter V8 ) Sensor 1 would be close to the engine BEFORE the exhaust enters the catalytic converter
On a 2003 Ford Explorer , 4.0 liter SOHC , V6 engine : Bank 1 is the passenger side of the engine Sensor 1 would be close to the engine before the exhaust enters the catalytic converter
bank 2 is the drivers side of the engine sensor 2 is downstream of the catalytic converter ( after the exhaust has passed through the catalytic converter - called a catalyst monitor )
Bank 2 is the drivers side of the engine in your Ford Explorer Sensor 1 is in the exhaust , close to the engine , before the catalytic converter ( upstream sensor )
Bank 2 is the drivers side of the engine in your Ford Explorer Sensor 1 would be somewhere in the exhaust , close to the engine , before the catalytic converter
On a Ford Explorer : Bank 2 is the drivers side of the engine Sensor 1 would be close to the engine before the exhaust enters the catalytic converter
Bank 2 is the drivers side of the engine and sensor 2 is after the catalytic converter ( downstream ) on a Ford Explorer / F-150
Bank 1 is the passenger side of the engine in a Ford Explorer Sensor 2 is in the exhaust AFTER the catalytic converter ( downstream )