O2 sensor

[cutlassman_406]

I was just wondering if there was a way to check an o2 sensor by sight or somthing any comments would be helpful

[thesals]

you want to check an o2 sensor to see if it works??? all you need is a voltmeter.... output signal should range between 250mV and 650mV and it should
not stay steady.... if it seems locked at 450mV then its no good and will cause the vehicle to run in open loop... thats at least how you test it inside of
a running vehicle

[Craig]

Be carefull puting a volt meter on 02 sensor.
The voltage of the meter can screw the sensor!
It's junk if you do

[Matt167]

Be carefull puting a volt meter on 02 sensor.
The voltage of the meter can screw the sensor!
It's junk if you do

it's not going to screw up the sensor, it would fry the computer first. a DVOM would be needed for this, they are high impedence and do not harm computer circuits, an old analog meter would fry everything

[skids72]

For voltage sensing, your meter will be safe but if measuring resistance/impedence (ohm-meter mode) you can damage components...

I believe this is true for both DVM and the old analog style.

[thesals]

it's not going to screw up the sensor, it would fry the computer first. a DVOM would be needed for this, they are high impedence and do not harm computer circuits, an old analog meter would fry everything

i didn't even know anybody has an analog meter anymore....

For voltage sensing, your meter will be safe but if measuring resistance/impedence (ohm-meter mode) you can damage components...

I believe this is true for both DVM and the old analog style.

checking resistance damage things???? you dont check resistance with power in the system, and as long as you arent dealing with any small circuits in the computer you'll be fine.... its when you start dealing with amperes that you can destroy things

[Matt167]

i didn't even know anybody has an analog meter anymore....



checking resistance damage things???? you dont check resistance with power in the system, and as long as you arent dealing with any small circuits in the computer you'll be fine.... its when you start dealing with amperes that you can destroy things

if you check resistance with current flowing, you will fry the meter.

[Matt167]

For voltage sensing, your meter will be safe but if measuring resistance/impedence (ohm-meter mode) you can damage components...

I believe this is true for both DVM and the old analog style.

not true at all, a DVOM will put out less than 1v output in OHM mode, not enough to damage anything. checking a computer circut for resistance makes no sense anyway, volt testing is all that makes sense in a computer circut.

[skids72]

I'm referring to the sensor itself. The meter can put out up to 9V momentarily in measuring resistance. I work with very sensitive components (mageneto resistive sensors) and we use diode clamps on our meters to limit voltage to 0.6V for resistance measurements, without them we blow them out as low as 3V.

I don't know how sensitive an O2 sensor is compared to these things. I was addressing Craig's response above to the tune of "measuring the voltage is safe it's resistance measurements you need to be careful of".

Point I'm trying to make is you are not going to damage an O2 sensor by measuring the voltage.

FWIW,

Chris

[thesals]

yep, thats what i was meaning when i mentioned testing circuits in the computer.... its about the only place you can really screw anything up... everything else is pretty versatile