Test Front o2 Sensor?

[VeryFast2gDSM]

I got a sensor from a friend. He said he bought it new awhile back and has been on his car. But it doesn't seem to be reading. How can I test it?

 

[whiteboyz]

start the car and let it run until the vehicle is warm, which usually takes about five minutes. The oxygen sensors must be about 600 degrees Fahrenheit to provide an accurate reading. This will cause the engine to become very hot, so be careful.

backprobe the oxygen sensor's signal wire. Be very careful when using the backprobe, because the plastic connectors are often very brittle and can break easily.

Connect the positive lead from the digital voltmeter to the backprobe.

Connect the negative lead from the digital voltmeter to a good solid ground point on the chassis of the vehicle.

Turn the voltmeter on and set it to the 1 volt scale. The voltage of the O2 Sensor will fluctuate between 100 and 1,000 millivolts, which is 0.1 and 1.0 volts, so having a quality volt meter is important.

Turn the vehicle back on and check the reading on the voltmeter. The reading should fluctuate rapidly. If the reading stays at around 0.5 volts, ensure that the vehicle is fully warmed up. If the vehicle is warm and the 02 Sensor reading does not change, then there is a problem with the 02 Sensor.

Or you could use Map gas to induce a vacume leak.

Oh also if the O2 sensor was bad it would throw a CEL. you could also graph it using a scanner

 

[vinnybean]

You also need to check resistance across the two heater circuits. A bad heater won't allow the sensor to heat up to operating temp and may give you a skewed reading. Also check for power at the sensor + feed.

If you use MAP gas its to induce a high reading. .1 = lean - or not much much fuel. closer to 1.0 is rich so when you turn on the MAP gas you should see the reading jump to rich.