A/F ratio (oxygen) sensor compatibility Impreza (gg) 1.6 AWD

[subawu]

This is my first post, so hello 👋

I got the P0030 heater code on my 2004 Impreza 1.6 AWD (gg) station wagon. This is a Europe and Middle East only model i believe. I checked the resistance on the sensor heater and it was open circuit. So i bought the cheapest universal I could find and no surprise, the code returned.

Using a digital multimeter and the engine running, there is a constant +14V on one heater wire and what appears to be PWM on the other heater wire (the Heater GND controlled by the ECU). On this wire, the average voltage cycles from about 0.1 to 2V. With the ignition ON and engine OFF there is a constant 12V on Heater + and constant 2.7V on Heater GND. Meaning the circuit is only active when the engine is running. So, to me, this appears the heater circuit is normal.

If so, I suspect that the universal upstream sensor isn't to spec. And this leads to my question. What Denso sensor fits my model? I'd prefer not to buy a universal again, even a well known brand.

Impreza 1.6 AWD (gg) station wagon
Model: GG5DL4K
Year: 2004
Eng. type: EJ161NW6AB

I did look, a lot, but only found universals and many European sites cannot agree on whether they are even compatible with my car. The Denso European catalogue only recommends DOX-0120, but this is a universal.
ChatGPT claims that Denso 234-9015 is the right one, built to spec, but it's only available in the USA and there the suppliers don't list the 1.6 litre model at all, so i can't confirm the AI.

Does anyone know the OEM part number (is it 22641AA280 as ChatGPT says) or what specific wideband A/F ratio sensors were made for my car. Is that the right Denso?

Thanks