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Old 06-29-2008, 09:27 PM
TimFreeh TimFreeh is online now
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Quote:
Originally Posted by ps2cho View Post
Thats the reason I wanted to have the O2 sensor tell me if I was running lean or rich as I understand it gives 0.1v for lean and 0.9v for rich....so it should sit at or around 0.4v.
When operating in "closed-loop" mode the sensor is not going to "sit" at any one voltage for more than a few milliseconds, remember that the sensor is feeding info back to the ECU to adjust the mixture. As the ECU changes the mixture the voltage on the O2 sensor will swing from lean->rich and then back to lean. At idle this pattern repeats itself 2-4 times a second if you have a healthy sensor, maybe once a second or less with a "lazy" or sensor.

If you use a multimeter to watch the O2 sensor voltage you should see it oscillating from .1 to .9 volts in a seemingly random pattern. A scope gives a much more meaning full view of O2 sensor operation.
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