Hey there!
has anyone had this happen to them before???
I have my ECL on in my 03 wrx sti. Managed to borrow a scan tool to retrieve the fault code which is P0031 front o2 sensor (off manifold) heater control circuit low, bank 1 sensor 1.

So I bought a aftermarket 02 sensor to suit, (bosch). I've fitted it and cleared the code, and it hasn't made any difference. Light comes on after a minute when car is started and is the same fault code. I've correctly rewired all the terminals to the new sensor (not soldered either). Checked continuity from plug connector in engine bay to new wiring connecter on every wire. Checked that the sensor is getting power. Even disconnected other o2 sensor to make sure it was the right 1... Made sure I have the right part for the model car. Checked all fuses, even tho theres nothing stating A/F or o2 sensor..
Has anyone got any other suggestions to add??? Please help...