BMW X6 NOx Catalyst Failure Causing Power Loss

Hey there! I had a similar issue with my 2012 BMW X5 35i last year. The symptoms you're describing match what I experienced, power loss and check engine light. Initially thought it was just an exhaust leak, but during inspection, they found the NOx catalyst was deteriorating and causing increased back pressure in the system. The catalyst replacement was necessary as it was affecting engine performance and could've led to more serious issues if left untreated. My mechanic showed me the old catalyst, it was pretty badly clogged and had some cracks. It's definitely not a quick fix as they need to deal with multiple sensors and connections. The repair took about two days at my trusted mechanic's shop, and the difference in performance was noticeable right away. The engine ran smoother, and the power was back to normal. Make sure whoever does the work uses OEM parts, that's crucial for these systems. Just a heads up, it's a complex repair that needs proper diagnostic equipment and expertise with BMW emission systems. Hope this helps with your decision.

Thanks for sharing your experience! Really helpful to hear from someone who went through the same thing. I'm curious, do you remember roughly how much you ended up paying for the full repair? Also, has everything been running smoothly since then, or have you noticed any other issues pop up? Dealing with my X6's power loss is such a pain, and I want to make sure I'm prepared for what's coming. Your tip about OEM parts is spot on, definitely don't want to cut corners with this kind of repair.

Hey again! Happy to give you an update! Since my last reply about my X5, I'm glad to report everything's been running perfectly. The total repair came to 265 € for fixing the exhaust leak, which turned out to be the main culprit. The NOx storage catalyst aging issue was actually sorted during the repair too, what a relief! The car's been running like a dream since then, no power loss, no warning lights, nothing. It's been about 14 months now, and honestly, the engine feels as responsive as ever. That OEM parts recommendation I made earlier? Definitely stood by that, and it's proven to be worth every cent. Really glad I went through with the repair when I did. Left untreated, these issues can snowball into bigger problems. From what you're describing with your X6, sounds exactly like what I dealt with. If you're still shopping around for a mechanic, just make sure they've got solid BMW experience, it makes all the difference with these specialized repairs. Let me know if you need any other details about the repair. Always happy to help another BMW owner!

Thanks so much for all the detailed info! Actually, I bit the bullet and got my X6 fixed last week. Got a trustworthy mechanic who specializes in BMW, just like you suggested. The whole thing set me back about 300 €, but honestly, it was worth every penny. The mechanic found a small crack in the catalyst and some sensor issues. They replaced everything with OEM parts and did a thorough check of the entire system. I was nervous at first, but watching them work, I could tell they knew their stuff. The car's running amazing now, that annoying power loss is completely gone, and no more check engine light! It's like driving a different car. You were right about getting it done quickly before it caused more problems. Really appreciate you taking the time to share your experience. It definitely helped me make the right decision with my repair. Guess we both learned that when it comes to these BMWs, doing things right the first time saves a lot of headache later!