Get the actual number code for it and call your local carquest or autozone and they will tell you what it is.
The Northstar engine uses two O2 sensors. Sensor 1 is located on a bung in the exhaust after the manifold, but before the catalytic convertor. Sensor 2 is located after the catalytic convertor. It's that simple.
On a 2001 Ford Mustang , 3.8 liter 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 1 is the passenger side of the engine ( V6 and V8 ) in a 2001 Ford Explorer Sensor 1 would be close to the engine before the exhaust enters the catalytic converter
Need more info, is this the 4 cylinder or 6 cylinder engine and which sensor on bank 1.
Bank 2 is the passenger's side of the engine and sensor 2 is behind the catalytic converter on that side.
Bank 2 is the drivers side of your Ford Mustang engine Sensor 1 is somewhere between the engine and the catalytic converter
bank 2 is the drivers side of the engine and sensor 2 is downstream of the catalytic converter
Bank 1 is the drivers side of the engine and sensor 1 will be the closest O2 sensor thats in the exhaust pipe where it bolts to the engine exhaust manifold.
Bank 1 is the passenger side of the engine in your Ford Mustang Sensor 1 would be in the exhaust close to the engine before the exhaust enters the catalytic converter ( upstream )
Bank 2 is the drivers side of the engine in your Ford Explorer Sensor 2 is after the catalytic converter ( downstream )
Bank 2 is the drivers side of the engine Sensor 1 is before the exhaust enters the catalytic converter ( upstream )
On a 2001 Lincoln Navigator : Bank 1 is the passenger side of the engine Bank 2 is the drivers side of the engine Sensor 1 ( on each side of the engine ) is close to the engine before the exhaust enters the catalytic converter ( upstream sensor used to help the Powertrain Control Module ( PCM ) adjust the fuel ratio Sensor 2 ( on each side of the engine ) is after the exhaust has passed through the catalytic converter ( downstream sensor , also called the catalyst monitor )