CT200h Oxygen Sensor Issue

I had a similar issue with my CT200h. The exhaust sensor was the culprit. Have you checked the O2 sensor connections? Sometimes it's just a loose plug.

Thanks for the quick reply. Where exactly did you find the defective connection? Was it visibly corroded?

I didn't find the connection myself; the workshop diagnosed it. They mentioned the readings were erratic, pointing towards a faulty sensor or its wiring. They suggested replacing the sensor and cleaning the contacts. I'd recommend getting it checked professionally. This could become an exhaust system issue.

Took it to the shop as suggested. Indeed, aged oxygen sensor. Cable and plug connection were defective. Repair cost 95€. Thanks for the advice!