Originally Posted by Balboa
The wire for the front O2 sensor is still plugged into the O2 sensor, which is in place.
If it was a CEL fix for the rear O2 sensor, it was a failed attempt.... Took out the oxygen sensor today and found there is a hole burned through the top -- switch sensor with my dad's '05 WRX for our long trip tonight and tomorrow.
I'd take a look at the EGT sensor. The passenger of the vehicle a wire with some type of heat sheilding running to the uppipe below the turbo. If I recall correctly the sensor plugs in below that little plastic cover on the passenger side. You won't be able to easily see the sensor but you should be able to feel around for it from the top when you trace the cable. I removed mine and replace with a bolt and resistor.