The front oxygen (air fuel ratio) sensor element may develop a crack, causing the Check Engine Light to illuminate. Subaru has recalled certain models to replace sensors that may fail. The Subaru service program number is WXW-80, this is not a government mandated recall.Google+
Car Problem Reports
Subaru Legacy Subaru Front O2 Sensor Recall
Subaru Legacy Problem
Average Mileage: 111,000 mi (62,000 mi - 160,000 mi)
I've had a Bank 1 O2 sensor code (0420) since purchasing my car used in 2010. The check engine light came on within the first week of owning it. It has been an ongoing issue every year trying to get it inspected. I'm told it's more that the converter is shot. It would be great to find out if my car fits said recall. Especially since replacing the converter would be ridiculously expensive for me!