DTC P0031 Questions

[4goingfast]

I have a 2002 WRX Wagon that I just purchased used. It has a P0031 code which says it is a HO2s Bank 1 Heater Circut Low.

I can not find the Oxygen Sensor.

Question, what side of the car is Bank 1. Driver or Passenger?
Where is the O2 sensor locater?

I have a repair manual on order, but have some time next week and would like to get the thing replaced.

Any help, pictures, extc would be appreciated.

Thanks

[4goingfast]

I found a similar thread from a while back, and Schrags had pictures and instructions on how to locate the HO2 sensor, how to remove the heat shield, how to modify the heat shield so that it will come off without taking to sensor out first, and got the new sensor in.