BMW X6 Emergency Mode: Bad Sensor Causing Power Loss?

Had a similar issue with my 2014 BMW X5 35i. The symptoms you're describing match what I experienced, poor fuel economy, limp mode, and CEL. Turned out there was a crack in the downpipe near the flex joint, causing exhaust leaks. The sensor was picking up incorrect readings, forcing the engine into safe mode. The mechanic found it during a smoke test. It wasn't a quick fix since the whole downpipe section needed replacement, but it was necessary to prevent damage to other components. Keep in mind that exhaust leaks can be dangerous due to fumes, so I wouldn't put off getting it checked. Since you've got low mileage, this might be covered under warranty, worth checking with BMW. My case was pretty serious since the leak was affecting engine performance and could've damaged the catalytic converter if left unchecked. After the repair, everything went back to normal, power restored, fuel economy improved, and no more CEL.

Thanks for sharing your experience! That's really helpful, sounds exactly like what I'm dealing with. Would you mind sharing how much the downpipe replacement set you back? Also, has everything been running smoothly since the repair, or have you noticed any other issues pop up? Really appreciate your insight on this.

Hey there! Happy to give you an update on my situation. I just got my X5 back from the shop last week. The final bill came to 265 € for fixing the exhaust leak, which wasn't too bad considering what it could have been. They found and replaced the faulty exhaust temperature sensor too, which was actually the main culprit causing all those annoying symptoms. Since the repair, my car's been running like a dream, honestly, it feels better than ever! Power's back to normal, fuel consumption is much better, and that annoying check engine light is finally gone. No other issues have popped up, and the engine's purring along just like it should. I'm actually really glad I got it sorted when I did. The mechanic mentioned that letting these kinds of problems go on too long can lead to bigger headaches down the road. If you're still having the same symptoms, I'd definitely recommend getting it checked out soon. The peace of mind alone is worth it!

Just wanted to update everyone on my BMW situation. Finally took it to the mechanic yesterday, and boy am I glad I did! The issue turned out to be pretty similar, a damaged exhaust sensor plus some wear on the connecting pipes. The repair cost was a bit steeper than expected at about 400 though, but watching the car run smoothly again makes it worth every penny. The mechanic was actually super helpful this time. He showed me exactly what was wrong and explained everything clearly, totally different from my last experience. Got the car back today, and what a difference! No more check engine light, power's back to normal, and it's not guzzling fuel like crazy anymore. Thanks again for all the advice, especially about not waiting too long. You were right about catching it early, the mechanic mentioned a few months more and it could've caused some serious damage. Really appreciate everyone's help on this one!