RC oxygen sensor failure

Hey, I had a similar issue with my old Opel Astra, although not exactly the same, the symptoms sound very familiar. High fuel consumption and the check engine light were the first signs. Did you check the wiring harness for any obvious damage or corrosion?

Yeah, I gave the wiring a quick look, didn't see anything glaring. But it's kinda tight in there, could easily be something I missed. When you say 'wiring harness', are you talking about the bit that connects directly to the O2 sensor?

Exactly, that's the one. On my Astra, it turned out to be a corroded connector. Check closely, and if you can't find anything obvious, maybe it is better to have it checked in a workshop. It may also be the sensor itself, but better check everything before replacing it.

Appreciate the tip about the wiring, I'll give it another, closer look. Just got a quote for 95€ to fix it, so if I can find the bad connection myself, I'll save a bundle! Cheers!