So it was finally a flying day today and I paid close attention to the AFR gauge. It definitely appears to still be working. Readings as follows.
Master on - 14.7 then after a few seconds increasing to 15+
Engine start - decreasing down to 12.5 full rich - 1000rpm
Ground lean at 1000rpm - increases to 15
Runup at 1800rpm full rich - decreases to 12
Ground lean for taxi - increases to 15
TO full rich - 11.8 throughout the climb and into cruise
Cruise 2390rpm 60% power (Dynon), LOP(Dynon) AFR 15
At full power on climb out the gauge reading was pretty steady at 11.8. At the other power settings the reading bounces around quite a bit both above and below. The numbers listed are about the average.
I have 666.2 on the hobbs and the AFR gauge and sensor were installed at 60 hrs. I have only run 100LL and always lean except for TO. Can't explain why my O2 sensor still functions when so many fail between 10 and 50 hrs.