P0031 Code

[scoobaru03]

Heated Oxygen Sensor Heater Control Circuit Low (Bank 1 Sensor 1). Finally a code popped up for the wagon. This is the only one on. Now Would Bank 1 be the right side of the engine and sensor 1 be the sensor in the right side header?

[SD_GR]

There is only one Bank.

The sensor to which you refer is the front sensor; side isn't relevant as there's nothing on the other side. See this thread and follow the links therein:

O2 Sensor :(

[scoobaru03]

yea strange thing happened when i was doing the diag i got 14.XX volts on power on the the harness side of the connecter for the A/F sensor. Then i checked the ground side and it dropped to about 10.XX. i figured 4 volts was alot of voltage to drop. I figured i had high resistance somewhere in the wire between the computer and the connector but it checked out ok. Long story short the A/F sensor was open so i get to spend some more money..yay...but i was wondering if anyone knew why the ground side would drop about 4 volts like that with normal resistance.