Originally Posted by TurboAWD
I had same problem, same code, back in August. Took long time to figure it out, but turned out it was the front O2 sensor. For whatever reason, it wouldn't regularly trip a code, and everything seemed fine, and just when the tuner was about to start pulling his hair out, the sensor failed completely.
So it was a headache, and it wasn't cheap, but it was resolved.
That's funny cause I've actually had this code read out before and just googled it.
The first link was to a legacygt thread saying to change the front O2 sensor. Bought one online and changed it out in 5 minutes and boom, no more code
Unfortunately this time it wasn't so easy...