Octavia Oxygen Sensor Issue

Sounds familiar! I had similar issues with my Octavia: check engine light, guzzling fuel like crazy. It could very well be the oxygen sensor, especially with that mileage. Have you checked the wiring and connectors? Sometimes it's just a loose or corroded connection causing the problem.

Interesting! When you say 'wiring and connectors,' are we talking about the ones directly connected to the oxygen sensor itself? And did you experience any rough idling or other weird engine behavior besides the fuel consumption?

Yep, the connectors right on the oxygen sensor itself. Give them a good look for corrosion or damage. And no, I didn't have rough idling, just the check engine light and terrible fuel efficiency. If cleaning the connections doesn't fix it, you might need a new sensor, but definitely rule out the simple stuff first. An oxygen sensor, by the way, is responsible for measuring the amount of oxygen in the exhaust gases to ensure the air-fuel ratio is optimal. If you are not comfortable doing it yourself, take it to a workshop.

You nailed it! I took my 2008 Octavia to the shop, and it was exactly as you described: a dodgy connection on the oxygen sensor. They cleaned it, reset the error, and so far, so good. Fuel efficiency seems better already. 95€ all in. Thanks a million for the heads-up!