V40 Oxygen Sensor Heater Fault

I had a similar issue with my Opel Astra. Check engine light and high fuel consumption. The code also pointed to the oxygen sensor heater. In my case, it was a corroded connector. Have you checked the wiring and connector for corrosion, damage, or loose connections? Also, is it the pre-catalytic converter sensor or the post-catalytic converter sensor?

Thanks! My understanding of car electrics is basic. Can you explain where the oxygen sensor connector is? And how do I tell the pre-catalytic converter sensor from the post-catalytic converter sensor?

The oxygen sensors are in the exhaust system, screwed into the exhaust pipe. The pre-cat sensor is before the catalytic converter (closer to the engine), and the post-cat sensor is after it. You'll probably need to jack up the car to access the connector. Given your lack of experience, I'd recommend a workshop. A mechanic can diagnose it properly and it's not a costly repair. I only spent 80€ for the oxygen sensor and 15€ for the labor costs, so 95€ total.

That's wonderfully clear. I understand the sensor positions and the need for a professional diagnosis. I'll book an appointment with a trusted mechanic to check the connector and sensor. Thanks for the expertise and guidance!