The more I think about your problem the more I'm convinced the O2 sensors aren't bad and it's the heater wiring. I wouldn't think both sensors would go at the same time. And the common tie in is that heater wiring. I would competely inspect and check out the heater wiring circuit right where it starts at the relay panel in front of the battery.

Check out page 25-5 and 25-1 of the electrical manual.

1998 Sportage - Gone.
2004 Honda Civic Coupe.
2007 Suzuki Grand Vitara - She got it.