Single wire O2 help

[Webby_roller]

Hey guys, I am just wondering if anybody knows the general way the single wire O2 sensor works.

I know how a O2 sensor works, I was just wondering if the O2 sensor grounds to the headers and works that way?

Any info would be a great help.

Cheers

[Simmo2302]

been a long time since i read up on o2 sensors but from a few years back i read up on 1 - 4 wire o2 sensors and from what i can rememebr is

1 wire - wire is positive, grounds thru exhaust.
2 wire - 1 positive, 1 negative.
3 wire - O2 sensor w/ inbuilt heater. 2 positive 1 common earth.
4 wire - O2 sensor w/ inbuilt heater. 1 set of + & - for each.

could be wrong though, may also vary from make and model was researcing ford falcons at the time. hope that helps

[Webby_roller]

If it is supposed to ground through the exhaust and it isn't, does this indicate a bad sensor?

I have done the test to see if it is a full circuit back to the battery and it is telling me that the sensor isn't grounding, any ideas anyone!!!

I have tested from sensor to ECU, and it has a broken circuit, which i am about to fix now. Then i tested sensor to ground and it says it is a broken circuit and not grounding.

Cheers

[Simmo2302]

cool, just replace the sensor :-)

cant realy remember and i m sure it will change between makes and models of cars but i think the ECU runs the O2 sensor runs on a closed circuit, ie it ignores the informaton recieved from O2 sensor untill high rev i think, ie highway driving.

or maybe its the other way round, ecu ignores info received from O2 sensor at high rev (closed circuit) but goes open circuit (ie relies on the info from 02 sensor) at idle to adjust air fuel mixture

cant really remember, someone will have to correct me on this one.

either way you should get a reading on your multimeter when testing between the single wire on the O2 sensor and the grounded chassis. if no reading sensor is broken :-)

[Webby_roller]

EXCELLENT!!! Cheers for that.... Will get on it first thing this weekend!!!

[ECU-MAN]

single wire O2 grounds throught the exhaust manifold

[Webby_roller]

If it isn't grounding, is this a sign of a faulty sensor?

[ECU-MAN]

yep...

what brings you to the conclustion ist not grounding

[Webby_roller]

Continuity test between sensor and ground...

[ECU-MAN]

the sensor body is the ground of the sensor, you wernt doing a test from the O2 wire to ground where you ??

[Webby_roller]

I disconnected the connection that is closest to the O2 sensor and tested from there to ground.

Is this an issue?