Looks like my O2 sensor failure might have been caused by using too hot spark plugs. The failure occurred awhile after I installed E3 Diamond Fire spark plugs on the advice of a friend. Since then I've had several ignition components fail along with the O2 sensor, and a mechanic traced it to the plugs causing a domino effect of component failures by putting a strain on the ignition and emissions systems. Best to stick with stock Denso plugs if you haven't beefed up the rest of your systems. Mine is stock and stock Hondas are very sensitive. $2000 lesson learned. I have since heard from another friend who tried the E3 plugs in an Audi and had the same problem later on. Fried the coil...