BMW Check Engine Light: O2 Sensor Drama at Low Miles

Hey there! I had a similar issue with my 2013 BMW 2 Series last month. The symptoms matched yours, check engine light, poor fuel economy. Turned out it wasn't the O2 sensor in my case. The technician found a loose connection in the wiring harness that connects to the engine control unit. Some pins were corroded and making poor contact. The fix wasn't too complicated, cleaning the connections and replacing a damaged section of the harness solved it. It wasn't a serious problem, but leaving it unfixed would've continued causing poor performance and potentially led to bigger issues. My advice would be to have a proper diagnostic done first before replacing parts. Sometimes these symptoms can be misleading. I was convinced it was the O2 sensor too, but a thorough check saved me from unnecessary replacements. Just make sure to find a shop that specializes in BMW or at least European cars, they'll be more familiar with these specific issues. Best of luck with the repair.

Thanks for sharing your experience! That's really helpful to know it was just the wiring harness in your case. If you don't mind me asking, how much did they charge you for the fix? Also, has everything been running smoothly since then, or have you noticed any other issues pop up? I want to get a sense of whether I should prepare for any follow-up problems.

Hey again! Actually, I need to correct my earlier post, in my case, it did turn out to be the aged oxygen sensor after all, not the wiring harness as I initially mentioned. I just got back from the mechanic last week, and they found it was a faulty cable connection to the O2 sensor that needed fixing. The total bill came to 95€, which wasn't too bad considering I was worried it might be something more serious! Since the repair, my BMW's been running like a charm, fuel economy's back to normal and that pesky check engine light hasn't shown its face again. No other issues have cropped up either, so I'd say you shouldn't have to worry about follow-up problems once you get it sorted. Just goes to show how important it is to get a proper diagnosis. Even though I thought it might've been something else at first, having a competent mechanic really made the difference in identifying and fixing the actual problem. Hope this helps with your situation! Let me know how it goes when you get yours checked out!

Thanks so much for the update! I actually took my car in yesterday. Turns out my case was pretty similar to yours, it was indeed the O2 sensor causing all the trouble. The mechanic I found was really thorough and explained everything clearly. The whole thing, including parts and labor, cost me around 120 bucks. Not too bad considering how worried I was! The best part is the car's running perfectly now. The check engine light is gone, and I can already tell the fuel consumption is much better. Definitely a relief it wasn't anything more serious. Finding a good mechanic was the key, this guy really knew his stuff and didn't try to upsell me on unnecessary repairs. Thanks again for helping me out with your experience. It really gave me the push I needed to get it checked out properly rather than sitting around worrying about it. Guess sometimes the simplest explanation is the right one!