Oxygen Sensor There are actually (4) O2 sensors on your truck. If you look inside the wheel wells behind the fender liner, right about where the frame is one O2 sensor, the other is underneath the truck about half way back in relation to the transmission. If you see where the exhaust joints together, you went about 6" too far.
When you start looking at the O2 sensors, they are normally numbered something like "Bank 1 Sensor 1" Bank 1 is on the passenger side; Bank 2 is on the driver's side. Sensor 1 is the upstream sensor (near the frame, between the block and the cat) and Sensor 2 is near the Y-pipe (downstream of the cat).
Normally it is the upstream sensors (sensor 1) that go first. They see the harshest conditions. You will need; Oxygen Sensor Socket Anti-Seized Penetrating Oil Sometimes it will take 15 minutes or take a few hours it depends on your luck…
Bank 2 is the drivers side of the engine in your Ford Expedition
On a Ford Expedition : Bank 1 is the passenger side of the V8 engines
On a Ford Expedition , Ford F-150 , 5.4 liter V8 engine : ( bank 1 is the passenger side of the engine )
A 1997 Ford Expedition 4.6L V8 has an oil capacity of six quarts.
On a 1997 Ford Expedition : The 4.6 liter V8 engine uses ( 4R70W ) The 5.4 liter V8 engine uses ( E4OD )
On a Ford Expedition ( 4.6 and 5.4 litre V8 engines ) Bank 1 is the passenger side of the engine
On a 1997 Ford Expedition , 5.4 liter V8 : Bank 1 is the passenger side of the engine Sensor 1 would be close to the engine BEFORE the exhaust enters the catalytic converter
In the 1997 Ford Expedition , either the 4.6 liter ( 281 cubic inch ) V8 engine or the 5.4 liter ( 330 cubic inch ) V8 engine
it is under front bumper on drivers side...this is on a 1997 expedition 4x4
On a 2000 Ford Expedition , 4.6 or 5.4 liter V8 engines : Bank 1 is the passenger side of the engine and Bank 2 is the drivers side
In a Ford Expedition : Bank 1 is the passenger side of the 4.6 and 5.4 liter V8 engines
Either the 4.6 liter - SOHC - V8 or the 5.4 liter - SOHC - V8 , that was the 2 engines available