The electrical mechanism that computes the resistance of electrical in energy is referred to as an ohmmeter. These are sometimes used to check oxygen sensors; however some ohmmeters may cause damage to a Zirconia o2 sensor if used to check it.
The damage usually occurs with Zirconia o2 sensors when the ohmmeter is used to check it as the ohmmeter applies an additional voltage.
These symptoms may be evident if you have a failing oxygen sensor
1.   Sensor Light on dash indicates problem, although the sensor light may be due to another cause.
2.   Increased tailpipe emissions, this could mean that the oxygen sensor is not working properly so the Engine Control Unit is not getting any data and as such has to estimate the fuel and gas mixtures,
3.   Increased fuel consumption
4.   Hesitation on acceleration
5.   Stalling
6.   Rough idling
When an oxygen sensor stops working or begins to fail, the owner of the automobile may think that his vehicle needs a tune up or that he needs to change service parts, this is due to the fact that the symptoms of a failed o2 sensor can be very similar to those of a car that needs servicing. Some of these symptoms are listed above.
Oxygen sensors do not have an unlimited life span, but the ones made in recent years are made to last longer than the ones initially developed, the previous o2 sensors had scheduled maintenance times in order to ensure proper functionality. With the development of the new type of o2 sensors, most times there is no maintenance and oxygen sensor is usually only replaced if it fails or is beginning to fail. Oxygen sensors can fail for many reasons, some of which may include;
1.   The unit has surpassed its designed life expectancy, meaning that it has done its time and have gone through its expected wear and tear.
2.   The vehicle is burning too much oil causing the oxygen sensor to become corroded or covered in oil based soot, thus making the sensor not operate properly
3.   Internal engine antifreeze has leaked and has contaminated the o2 sensor, some antifreeze has silicone base and that is not good for the o2 sensor, once it gets contaminated with silicon based products it may start to fail.
4.   Internal contamination by silicone from any other source such as silicone based grease, sprays and gasket material among other things.
5.   The oxygen sensors have become encrusted with other remaining chemicals, thus causing it to malfunction.
6.   Other contamination caused by other automotive chemicals that is used for instance under coating solutions and other agents of that sort, if used within close proximity to the oxygen sensor.
7.   If the automobile uses fuel that contains lead, it may cause a build up and contaminate the sensor.