Rich is right. I use an oxygen sensor to tune my 2 stroke (to within an inch of its life. . .).
It is a heated, wideband sensor, hooked up to my Aim system.
I have to turn the heater on 60-70 seconds before I start the engine or it will be INSTANTLY fouled. Oh, and once fouled it is done for. I suggested dipping the sensor in boiling nitric acid or some such, but the manufacturer said that nothing could clean the ceramic pores. . . We'll see.
As far as lifespan, they said that properly heated, a sensor should last longer than an EGT sensor (which still isn't very long, so I only use the sensor when I am tuning for fuel), in an oil rich environment.
And reducing oil for such a test. . . Surely you can figure out a half dozen reasons this would screw you up and make the test of no value? :blah:
And to work WELL, you need to use it to adjust low, mid, and full throttle, which means recording the data. Though I suppose you could find a long abandoned highway. . .
I tune for fuel based on Oxygen, EGT's, piston wash, CHT, spooge, header inside color (which gets very weird out on the edge), and very lastly and leastly plugs.
And there is debate on location of the sensor. Best info I could find on 2 strokes was on the largest diameter of the exhaust, a couple inches behind the prior cone.