Megane Oxygen Sensor Faulty Connection

I had a similar headache with my Megane. It felt like the car was drinking fuel! The check engine light was on, throwing codes left and right. Have you checked the sensor's wiring harness for any obvious damage or corrosion? It’s like trying to find a needle in a haystack, I know, but sometimes it’s right there in front of you!

Good point. Where exactly should I be looking for this wiring harness? Any specific areas prone to corrosion or damage?

Okay, so picture the exhaust system as a tree, and the oxygen sensor is a little bird sitting on one of the branches. Follow the 'branch' (exhaust pipe) from the engine. The wiring harness should be close to where the sensor screws into the exhaust pipe. I'd strongly recommend taking your car to a trusty workshop. They have the right tools and probably a better view under the car than you or I do. Plus, they can properly diagnose and replace the sensor if needed, ensuring everything is sealed up tight. A new sensor plus labour cost me around 95€. It’s like having a proper doctor check you out instead of just self-medicating based on internet advice.

Appreciate the tip. Ended up taking it in, and you were right. It was a faulty connection. New sensor, and the light's gone. Thanks!