How can you bench test an 0xygen sensor?

There are such things as sensor simulators and testers that are fairly universal, very expensive and understandably quite rare though bench testing an oxygen sensor wouldn't be very helpful as a sensor could be electrically fine but be internally coated from use in an oil burning engine or from fuel impurities or from unburned fuel entering the exhaust, due to a dribbling fuel injector, bad spray patterns or too high fuel pressure, for instance.

Far better to test the sensor in situ. Many of the better obd code readers will display live data and indicate the state of the O2 sensor and a wide variety of software is available for standard laptops.
An oscilloscope is another excellent method of testing but experience is needed to interpret the results.

There are cheaply and widely available O2 testers that are essentially led voltmeters designed to operate in the 0 - 1 volt range so it is possible to see the sensor pulsing satisfactorily in the correct voltage range. They are designed for diy use and arrive with instructions.

When we detect a lean mixture code from our vehicles, our first reaction may be to replace the oxygen sensor. However, testing oxygen sensors before replacing them is a good idea. The best way to check the operation of the sensor is to run a simple test. And all you need is a voltmeter. A voltmeter is usually cheaper than car diagnostic tools and is available within 100 eurs. Here I will use an original Autel PowerScan PS100 for 56 eurs from EOBD2.FR.
How to check if your oxygen sensor is bad and needs to be replaced:
Step 1. Find the oxygen sensor sensing wire, connect Autel PS100 to the feedback wire and ground and then choose the mili volt operation.
Step 2. Turn on the ignition key to start the vehicle and run the engine at idle to warm it up. Watch data on PS100. The voltage should move slightly at whatever voltage the sensor is centered at.
Step 3. When you pull the oxygen sensor data stream up, the output voltage from the sensors should constantly bounce between high and low with the meter dropping and rising, as the engine is running in closed loop. The volt meter should stabilize at the original operating voltage when the engine returns to idle.
If your oxygen sensor does not show the above reactions, it is probably that it is bad.
Note: If the error code shows a malfunction exists with related components such as an engine misfire or other engine problems, please do not perform this test.

I found this online for you.
Possible causes for this check engine light code include:
Blown oxygen sensor fuse
Open circuit in oxygen sensor harness
Open circuit internal to oxygen sensor
Open circuit in PCM
Short circuit in oxygen sensor harness
Short circuit internal to oxygen sensor
Short circuit internal to PCM
Diagnostic Help: To diagnose a P0061 check engine light code we will need to test out the oxygen sensor wiring and also test the circuits through the oxygen sensor itself. The internal processor circuits are a possible cause but are much less likely, so the other areas are thoroughly tested first. See our article Automotive Circuit Testing 101, if you need more assistance with this. If concern is determined to be intermittent, check out our article on Intermittent Diagnosis and wiggle test connectors and wiring, attempting to duplicate concern. You may also use the "Get Help" link if you need specifications or have any other related questions. Remember to refer to an appropriate manual for specific instruction.

always the Oxygen sensors is located at exhaust manifold , end
of the silence pipe ,before and after the environment filter .

flashing lites means dont drive .bad things will happen in motor. something emission related messing with exaust ' dont drive!!!! take to smog tech'

check the exhaust, under the car, or if it's front wheel drive may be right on the front of the engine on the exhaust manifold.

Hello there and welcome to fixya
Remove the oxygen sensor connector cover and check the oxygen sensor's operational voltage. Consult your vehicle's manual to find the wiring schematic. Back probe the sensor's connector with the meter leads. Start engine again and monitor voltage readings. Voltage should switch between high and low, from approximately 0.1 to 0.9 vdc. Replace sensor if it fails this test.
3

Unplug the sensor connector and test the sensor's heating circuit. Using your vehicle's wiring schematic, check for 12 vdc and also for a good ground. If voltage or a ground is not present, repair circuit between connector and battery.
4

Measure internal resistance of the sensor's heater circuit. Check that the heater resistance is a low reading. Replace sensor if the heater resistance is infinity or extremely high.
5

Unplugging the sensor's connector while testing the oxygen sensor will often set fault codes and illuminate the "Check Engine" light. After all checks and repairs have been made, clear the fault codes by following the procedure in your vehicle's

Read more: How to Test Oxygen Sensors ' eHow.com http://www.ehow.com/how_4780847_test-oxygen-sensors.html#ixzz1hPBA4wKH

Try to retrieve the actual code by using a code scanner. Usually when the code definition is "Bank 1 Sensor 1" --- this is the upstream oxygen sensor closest to the engine bank with cylinder no. 1 on it. If the engine is a "V-6" , you might get "bank 2" for the side of the engine opposite cylinder no. 1.

"Sensor 2" on the other hand, indicates the downstream oxygen sensor; or the one after the catalytic converter.

I hope this helped,

Have a great day !!!

oxygen sensor? You haver a front and rear. Usally just a wire broken. Need DTC Code from Autozone for free. Then we will solve issue.

http://groups.yahoo.com/group/villagerquest/

It sounds like you have either a lean or rich condition ocurring,could be exuast leak,vac leak,leaking fuel preasure regulator,cat convertor.At this point would go to dealer for diagnosis.