Black smoke, loss of power and NOx sensor defect

Hi, I had exactly the same problem with my 2006 BMW 5 series, my car knowledge is somewhere between low and somewhat, so I know a bit about cars. I went to the garage and they found that the NOx sensor cable connection/plug was faulty. They fixed it for 385 euros and since then the problem was gone. Could you tell me what model your BMW 3 series is and how many kilometers it has driven? With a little more information I might be able to help you better with what you should do next. Hope this helps!

(Translated from German)

Hey, thanks for your quick reply! My BMW 3 Series is an E90 335i, but it already has quite a bit of mileage on it, namely 214781 km. So the NOx sensor sounds plausible, I'll have it checked at the garage. It had its last service almost exactly a year ago, so maybe I should tackle that again. Thanks for the tip!

(Translated from German)

No problem, always happy to help! Given the mileage of your car, your assumption about the NOx sensor could well be correct. A regular service is of course always advisable, as this simply keeps the car running smoother and prevents any major damage. Next time you're at the garage, simply have the fault memory read out. That could give you an idea of what the problem is. And they could also take a look at the exhaust. Keep your fingers crossed that it's nothing major! Let me know when you know more. Good luck!

(Translated from German)

Hello and thanks for your further advice! I will definitely tackle the service and sort out the NOx sensor and exhaust check at the garage. I really appreciate your help, it's good to have someone who understands these things. I'll get back to you as soon as I know more. Thanks again and take good care of yourself! See you then!

(Translated from German)