Koleos oxygen sensor issue

I had a similar issue with my Koleos. Check engine light, higher fuel consumption. It was indeed the oxygen sensor. Have you checked the sensor's readings with an OBD2 scanner? That might give you a clearer picture.

Thanks for the quick reply. I did use an OBD2 scanner, and it pointed to the oxygen sensor. Did you also have any specific error codes related to wiring or the sensor itself, or just a general O2 sensor error?

It was a pretty generic O2 sensor error. I tried cleaning the contacts, but it didn't solve the problem long-term. Eventually, I took it to a workshop. They confirmed it needed replacing. Cost me around 95€ to get it sorted.

Thanks for confirming. Sounds like I'm heading in the same direction. I'll take it to the workshop to replace the oxygen sensor. Hopefully, that will resolve the fuel efficiency issue and clear the check engine light.