O2 sensors in 16v Vitaras

[jeremyisme]

Hi, Can anyone tell me if the O2 sensor in a 16v vitara/escudo engine is a wide band or a narrow band O2 sensor. Most narrow bands have only one wire coming out of it, but I notice mine has four! So it makes me think that it is a wide band.

Anyone know for sure?

Thanks

[SLOGQ]

It wont be a wide band dude, its just a narrow band Heated 4 wire O2 sensor. 2 wires are for the sensor and the other 2 are for the heater inside the sensor. You must have one of the later model Vitaras that had a 16 valve 1.6.

[jeremyisme]

Ok, thanks for that. Why did they heat them? Most other O2 sensors I have seen only had one wire so I was a little suprised.

Anyone know which of the four wires is the O2 signal? i.e. 0 - 1v (i think)

[oozuk]

on 4 wire sensors

sensor earth
signal
heater earth
heater power

the reason they heat them is because oxygen sensors don't work till there hot so on some model cars there heated to recieve a better reading under low load conditions , so the engine can tune to meet emissions