2 O2 Sensors, Why?

[almc2242]

I know that this is the Camry area. But my RAV4 has a 3SFE engine. Very simular to the 5SFE. Besides, Camrys, some came with the 3SFE.

Well, here goes. My exhaust manifold has two [2] O2 sensors. One says Oxygen Sensor (Bank 1 Sensor 1), and Oxygen Sensor (Bank 1 Sensor 2). What is the diffrence between the two?

[Joe W]

One sensor between the head and the cat provides input to the computer.The other sensor after the cat monitors the exhaust to make sure everything is fine tuned.

[88 LE]

Bank 1 sensor 1 is a pre-cat O2 sensor.

Bank 1 sensor 2 is a post cat O2 sensor.

The ECU checks for a difference between the 2 O2 sensors to make sure the cat is working correctly.

IE: If you were to remove the cat the ECU would throw a error code about the 2nd O2 sensor (Bank 1 sensor 2).

[Nico]

Funny here in Europe Camry's only have one O2 sensor, just before the catalytic converter

[rasman]

How about the Australian Camry's O2 sensor? how many are they?