For those of you interested, I just replaced my O2 sensor after 114hours of
using 100LL gasoline.  It lasted 114 hours of engine run time, however, the
last 30 hours it has been showing signs of decreased sensitivity, while
still useful in assessing engine conditions was starting not to show the
leaner Air/Fuel conditions.  So while lead gasoline may kill the usefulness
of an O2 sensor for computer control of emissions quickly, it takes a bit
longer for it to render it useless for air/fuel indications.  At $42.00 that
amounts to approx 36 cents/hour or about 2 years flying time at my present
rate.


Ed Anderson
RV-6A N494BW Rotary Powered
Matthews, NC
eanderson@carolina.rr.com