BMW X2 Oxygen Sensor Affecting MPG and Emissions

Hey there! I had similar issues with my 2020 BMW X3 last winter. The symptoms matched exactly what you're describing, high fuel consumption, check engine light, and emissions test failure. At the garage, they found the oxygen sensor heater circuit was failing. The connections had corroded, causing intermittent signal issues. They had to replace both the sensor and clean up the wiring harness connection points. It wasn't a major repair, but definitely not something to ignore since it affects both fuel economy and emissions. I've put about 25,000 km since the repair without any recurring issues. The fuel consumption went back to normal right after fixing it. Just make sure whoever works on it uses OEM parts, these sensors are pretty sensitive to quality differences. Good luck with the repair.

Hey, thanks so much for sharing your experience with the oxygen sensor issue! I'm really glad it worked out well for you. Been meaning to ask, do you remember roughly how much you ended up paying for the whole repair? Also, everything's still running smoothly with the sensor now? I'm trying to get a better idea of what I'm looking at cost-wise and whether I should expect any follow-up issues with my X2.

Hey again! Glad to give you an update! I just got my X3 fixed last week actually. The mechanic found it was exactly what we thought, the oxygen sensor heater failure. Turned out to be a pretty simple fix, just a bad cable connection to the sensor that needed sorting out. Only cost me 95 € which was a huge relief, as I was worried it might be something more serious! Since the repair, my car's running like a dream. The fuel consumption's back to normal and that annoying check engine light is finally off. Haven't had a single problem in the past week. Honestly, it's like a different car now, way more responsive and efficient. My advice? Don't put it off like I initially did. The repair was much quicker and cheaper than I expected, and it's definitely worth getting it sorted to avoid any potential damage to the engine in the long run. If you're worried about costs, what I paid should give you a good ballpark figure, assuming it's the same issue of course. Let me know how it goes when you get yours checked out!

Thanks for the detailed follow-up! I actually just got back from the mechanic yesterday. You were right about not putting it off, I bit the bullet and took it in. Funny enough, my issue was almost identical to yours. Found a new mechanic who specializes in BMWs and they sorted it out pretty quick. Cost me about 120 €, a bit more than yours but still way less than I was worried about. Turned out my sensor had a loose connection and needed some cleaning too. They got it done in about an hour and a half. Already seeing a huge difference, my fuel consumption's dropped back to normal and that pesky check engine light is finally gone. Took it for a good drive today and it's running super smooth. Really glad I didn't wait any longer to get it fixed. Thanks again for pushing me to get it checked out. Would've probably spent way more on extra fuel if I'd kept putting it off!