Peugeot 4008 Oxygen Sensor Failure

I had similar issues with my 4008: error codes, check engine light, and worse fuel economy. Have you checked the air-fuel ratio or exhaust system for anything besides the O2 sensor? Was the sensor tested?

I haven't checked the air-fuel ratio directly. How do I do that? The error is specific to the oxygen sensor heater. Is the sensor itself likely ok, or should I just replace the whole thing?

With a heater element failure, don't try a DIY repair. The sensor reading might be off even if it seems to work. Get it diagnosed at a workshop. I paid 95€, so expect something similar. They should check the emissions too.

Thanks. I'll get it checked at a workshop. Good to know about the repair cost. Appreciate the help!