Seat Arona check engine light and fuel consumption issue

I have a Seat Arona as well. Experienced similar symptoms. Error memory, check engine light, and increased fuel consumption. Suspect the O2 sensor. Have you checked the exhaust sensor and catalytic converter?

Did a defective cable or plug connection cause your issue, or was it the oxygen sensor itself?

For me, the cable and plug connection to the O2 sensor was the culprit. However, the workshop suggested replacing the oxygen sensor preventatively since it's related to the exhaust sensor and impacts the catalytic converter. I'd recommend visiting a workshop.

Acknowledged. The oxygen sensor and the plug connection were indeed the source of the problem. Car maintenance was carried out, and fuel efficiency has improved. Final repair cost amounted to 95€. Thank you for your input.