AEM AFR meter on the fritz!

Well, I replaced the o2 , and it worked fine, for 7 months...
Last night it crapped out again.
Sensors in new cars last for years. Any idea why I'm killing them so fast?
Mounted in the end of the driver's header collector, wiring on the fender apron, not touching the header. Fuel ratio never goes below 11.9 ( at idle). Never found any issue with wiring.