Is there and easy test to see if the oxygen sensor is working properly on a '91 S-10 4.3 L?

Thanks!

Good question.

A good rule of thumb is replace it every 50,000 miles or so...helps with fuel economy and driveability.

Is there and easy test to see if the oxygen sensor is working properly on a '91 S-10 4.3 L?

Thanks!

A voltmeter or a scanner.
Should have switching under and over .5 volts
The voltage long range is around .1 volt to .9 volts on a 02 sensor.
And watch the switching time.
Run engine full rich and see if it goes high.
Create a vacuum leak and se if it goes low.

If the O2 sensor had any problems with it, wouldn't it trip the "check engine" light?

I think MT-2500 has the right idea... that would be the way I would do it too.

A bad O2 sensor doesn't always trip the light. I believe that the car system gives it two minutes to read correctly and if it doesn't then it trips the light. An exception is if the car generally stays in range, but goes out of range and back in before the one or two minute mark. This is enough to give a rough ride but not turn on the light.

MT-2500,

What is meant by "switiching times" on th O2 sensor? What should it be?

Also, how do I create a rich mixture to check and is if it goes high?

THANKS!

Switching time is the time it takes a 02 sensor to swith voltage.
The older the get the slower the get.

MT-2500, What should the time intervals be between switching voltage?

How do I create a rich mixture for checking the 02 sensor hgh reading?