The Oxygen Senson #1 (Upstream) on a 1997 Isuzu Trooper is located under the vehicle and on top of the exhaust, just under the front passenger side. The easiest way to access and replace the O2 sensor, put the vehicle on a lift. Follow the exhaus pipe from the motor on the passenger side. There, you will see the #1 O2 sensor. First disconnect the o2's eletrical connection before removing (simple clip connector) An adjustable wrench will remove the O2. Replace with new O2, but do not overtighten! Reconnect the electrical connection. Done!
Driver side
Bank 1 is the side that cylinder 1 is on, sensor 1 is downstream and sensor 2 is upstream
The bank 1 sensor 1 oxygen sensor on a 2002 Honda Accord is located on the header. It is right next to the sensor circuit.
Bank 1 sensor 1 was the upstream 02 sensor located before the catalytic con on my 03.
There is no bank two on this van.
There are 2 catalytic converters on a V8 2002 Toyota Tundra. Bank 1 is the manifold and cat on the drivers side and bank 2 is the manifold and cat on the passenger side. Sensor 1 is the sensor on the exhaust manifold before the catalytic converter. Sensor 2 is the sensor located after the cat converter. Bank 2 Sensor 2 is the sensor located after the catalytic coverter on the passenger side.
Bank 1 would be the bank of cylinders that contain cylinder number 1. Bank 1 on the 3.9 would be the bank of cylinders located on the drivers side of the engine. Bank 1 sensor 2 would be the O2 sensor located after the catalytic converter.
On a 2002 Ford Crown Victoria : Bank 2 is the drivers side of the engine Sensor 2 ( downstream sensor ) would be in the exhaust after the catalytic converter
Bank 2 locates on the opposite side of the cylinder # 1 and the sensor 1 is locates in the front
Bank # 1 is the passenger side of the engine Sensor # 1 is before the catalytic converter ( upstream ) Sensor # 2 is after the catalytic converter ( downstream )
Bank 1 sensor 1 is closest to the firewall and located just below the exaust manifold. Easiest to change from under car.
Drivers side behind the convertor.