BMW X4 DPF Failure: Smoke, Power Loss, and Fix Advice

I had almost identical issues with my 2017 BMW X3 30d last year. The symptoms matched yours perfectly, power loss, warning lights, and that distinctive smoke under load. My exhaust back pressure sensor had indeed failed. The mechanic found it was giving incorrect readings, preventing proper DPF regeneration cycles. The sensor replacement fixed all symptoms, and the DPF started regenerating normally again. This is actually a serious issue since a faulty sensor can lead to complete DPF failure if left unattended. I'd strongly recommend getting it checked soon to avoid more expensive repairs down the line. The repair was straightforward and reliable, haven't had any issues since. Just make sure they test the new sensor's readings after installation. They should also clear all related fault codes and verify the DPF can complete a regeneration cycle. Best of luck with the repair.

Thanks for sharing your experience, it's really helpful to hear from someone who faced the same problem. I've been worried about getting it fixed, but your feedback makes me feel more confident about tackling the repair. Do you remember roughly how much you ended up paying for the sensor replacement? Also, has everything been running smoothly since the fix, or have you noticed any other exhaust-related issues pop up?

Hey there! Happy to give you an update about the sensor replacement. I paid exactly 245 € for the fix, which included parts and labor. It was totally worth every penny because the car's been running like a dream since then. Honestly, once they replaced that faulty exhaust back pressure sensor, all those annoying symptoms disappeared completely. The mechanic did a thorough job, they tested everything after installation and made sure the DPF was regenerating properly. Haven't seen a single warning light or had any exhaust issues since the repair, and it's been over a year now. The smoke during acceleration is gone, and the power's back to normal. My X3 feels like a different car now. If your symptoms are similar to what I experienced, you're probably looking at the same fix. Just make sure they do proper testing after the replacement, it's crucial for ensuring everything's working correctly. Trust me, getting it sorted sooner rather than later is definitely the way to go. You don't want to risk damaging your DPF, that's when things get really expensive!

Thanks so much for all those details! I just got back from the mechanic today, and you were spot on. They diagnosed the same issue with the exhaust back pressure sensor. Ended up paying a bit more than you did, but I'm just relieved it wasn't the entire DPF that needed replacing. The mechanic showed me the old sensor, it was completely shot. They did the replacement, ran all the tests, and even took it for a test drive to make sure everything was working properly. The car's already running so much better, no more warning lights, the power's back, and that annoying smoke is gone. It's such a relief to have this sorted. Really appreciate you sharing your experience, it helped me know what to expect and gave me confidence that I wasn't getting taken for a ride at the shop. Hopefully, this fix will last as long as yours has!