BMW X4: MAF Issues Causing Multiple Engine Problems?

Hey there! I had a similar issue with my 2017 BMW X3 last year (I have some experience working on cars as a hobby). The symptoms you're describing are exactly what I went through, rough idle, jerky acceleration, and that annoying check engine light. Took it to my trusted workshop and yep, it was indeed a faulty mass air flow sensor. The repair cost me 365 Euro, but it was worth every penny. The car runs like new now, smooth acceleration, stable idle, and better fuel economy. But before jumping to conclusions, could you share: Any error codes you're getting? When was your last maintenance service? Did these symptoms appear gradually or suddenly? With BMWs (I've also owned an X1), these symptoms could sometimes be related to other issues too, so these details would help us guide you better.

Thanks for your response! Just had these issues pop up about a week ago. My last service was only 2 months ago at 64,823 KM, and everything was fine until now. I got error code P0171, System Too Lean Bank 1. I ran a diagnostic scan myself before posting here. The symptoms started pretty suddenly, was driving normally one day, and the next morning, the car just wasn't the same. Your experience with the MAF sensor seems really similar to what I'm dealing with. Did you notice any improvement in fuel consumption after the repair? Mine's drinking fuel like crazy right now, and with current prices, it's really hitting the wallet hard. Think I'll get it checked out by a professional soon, just wanted to gather some insights from fellow BMW owners first. Thanks for sharing your experience!

Hey again! Yes, absolutely, the fuel consumption improvement after fixing the MAF sensor was dramatic! I was burning through fuel like crazy before the repair, probably 25-30% more than usual. After replacing the MAF sensor, it went right back to normal. That P0171 code you're getting is exactly what I had too. It's pretty typical for a faulty MAF sensor in these BMW engines. I remember being really frustrated because my X3 was running perfectly fine during the service, and then boom, all these issues just showed up out of nowhere. One thing I forgot to mention in my previous reply, before taking it to the workshop, I actually tried cleaning the MAF sensor myself with a special MAF cleaner spray (cost about 10 bucks). It helped for maybe a day or two but then the problems came right back. That's when I knew it needed replacement rather than just cleaning. The sudden onset of symptoms you're describing matches my experience perfectly. These sensors tend to fail quite abruptly rather than gradually deteriorating. Given everything you've described, the error code, sudden onset, and matching symptoms, I'd bet good money it's the same issue I had. Keep us posted on what you find out when you get it checked!

Thanks everyone for your input! After reading these responses, I feel much more confident about what might be wrong with my X4. Really appreciate you sharing your experience, especially about the fuel consumption improvement after fixing the MAF sensor, that's exactly what I'm hoping for! I've actually just booked an appointment with my mechanic for tomorrow morning. Going to mention the MAF sensor specifically, but will let them do their diagnostic check too. Good tip about the cleaning spray, might skip that step since it seems like a temporary fix at best. What's really put my mind at ease is hearing that someone else had the exact same error code and sudden onset of problems. Makes total sense that these sensors can just fail without warning. I'll definitely update this thread once I get the car checked out. Thanks again for all the helpful advice, this is why I love asking fellow BMW owners for their insights!