BMW 7 Series O2 Sensor Woes: Check Engine Light Alert

I faced similar issues with my 2011 BMW 5-series last month. The symptoms you're describing match what I experienced, check engine light and increased fuel consumption. Initially thought it was the O2 sensor too, but when I had it checked, it turned out to be a faulty cable connection to the sensor. The connector was corroded and had a loose fit. It wasn't a major repair, just needed cleaning and securing the connection properly. The mechanic also checked the surrounding wiring harness to ensure no other connections were compromised. Since you're dealing with a similar system, have your mechanic inspect the wiring and connections first before replacing the sensor itself. This could save you from unnecessary parts replacement. Make sure they use the right diagnostic tools and verify the fix by clearing the code and testing the car. In my case, it wasn't a serious issue, but leaving it unfixed would have led to catalytic converter damage eventually. Just keep in mind that these symptoms could also indicate other fuel system issues, so proper diagnosis is key. Best of luck with the repair.

Thanks for sharing your experience! That's good to hear it wasn't too serious in your case. Would you mind telling me how much you ended up paying for the repair? Also curious if you've had any similar issues pop up since getting it fixed? Really trying to figure out if I should expect just a simple fix or prepare for something bigger.

Hey again! Just wanted to update you, yes, happy to share the costs! For the repair, I paid 95 € which covered the labor to fix that corroded cable connection to the O2 sensor. Pretty reasonable, considering I was worried it might need a complete sensor replacement which would've been way more expensive. And you'll be glad to hear, since getting it fixed about a month ago, everything's been running perfectly. Fuel consumption is back to normal, and that annoying check engine light hasn't shown its face again. The aged oxygen sensor itself just needed proper connection, it was actually still working fine once they sorted out the wiring issue. Don't stress too much, based on what you've described, it sounds very similar to what I dealt with. Just make sure they do a proper diagnostic check first before replacing any parts. Sometimes these things really are just simple fixes! Let me know how it goes once you get it checked out. Always happy to help a fellow BMW owner!

Just wanted to give you all an update on my BMW situation. Finally got it sorted out today! Took your advice and found a mechanic who actually took the time to check the connections first. Turns out you were spot on, it was just a wiring issue near the O2 sensor. The connector had gotten loose and dirty over time. Only paid about 120 for the cleaning and fixing of the connection. Can't believe how much I was worrying about this! The car's running smoothly now, and that pesky check engine light is finally off. Fuel consumption has gone back to normal too. Saved a bunch by not having to replace the entire sensor. Really appreciate all the help and advice. Sometimes it really pays off to ask around before jumping to conclusions. Now I can finally stop stressing about this and enjoy driving my car again!