One problem related to o2 sensor has been reported for the 2012 Subaru Forester. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2012 Subaru Forester based on all problems reported for the 2012 Forester.
While idling in a parking lot, my Forester caught fire. The fire was put out quickly. So, the damage was fortunately isolated to the location where the fire started. It seems that the connector between the wiring harness and one of the O2 sensors on the front of the vehicle ignited. The fire burned the wiring harness near the connector and damaged the O2 sensor. Both needed to be replaced to repair my vehicle. This fire happened spontaneously and seems to be a safety risk . In my opinion, a 3. 5 year old vehicle should not spontaneously catch fire.