P0031 Fault Code on 2002 Subaru Impreza WRX - Heater Control Circuit Low

Model: 02 impreza wrx Fault Code: P0031 Posted: 2006-08-03 18:46

We recently replaced the front O2 sensor on our 2002 Subaru Impreza WRX with a new OEM part from Subaru, but the P0031 diagnostic code (Bank 1 Sensor 1 Heater Control Circuit Low) is still appearing. We've already performed voltage and resistance tests, all of which fall within Mitchell's specified ranges. Despite this, the code persists. Are there any additional troubleshooting steps or potential causes we should investigate next?