BMW X2 NOx Sensor Issues? Expert Tips and Cost Guide

Had the same issue on my 2015 BMW X1 last year. The check engine light came on and emissions test failed badly. Took it to the garage and they confirmed it was the NOx sensor, both faulty wiring connection and a damaged sensor. Not a super serious problem, but definitely needs fixing since it affects emissions and engine performance. The mechanic showed me corrosion on the sensor's electrical connector, which was causing poor signal transmission. They had to replace the sensor unit and rewire the connection harness. The repair took about 3 hours. Since then, no more check engine light and the car passed emissions easily. If your symptoms match (failed emissions, exhaust leak, error codes), it's likely the same issue. Just make sure they check both the sensor and the wiring, sometimes mechanics only replace the sensor and miss the connection problems.

Thanks for sharing that experience! Really helpful to hear your story since it sounds exactly like what I'm dealing with. Glad to hear it wasn't too serious in your case. Quick question, do you remember roughly how much you ended up paying for the whole fix? And has everything been running smoothly since then, or did any other related issues pop up? Just trying to get an idea of what I might be looking at cost-wise and whether I should expect any follow-up problems with my X2. Thanks again!

Hey, happy to give you an update! After my last post, I took it back to the mechanic for a small issue and they found it was just a faulty cable connection to the NOx sensor. Only cost me 95 € to fix, way cheaper than I expected! They didn't even need to replace the whole sensor unit like I initially thought. Since getting that sorted, everything's been running perfectly. No more check engine light, passed emissions with flying colors, and the exhaust system's working like new. It's been about 8 months now without any related problems popping up. Much better outcome than I expected, honestly. If your X2's showing the same symptoms, might be worth checking the wiring connections first before replacing the whole sensor. Could save you some serious cash. My X1's been running like a dream since the fix, no complaints at all!

Thanks for the follow-up! Just got back from the mechanic today and you were spot on. Turned out to be just a loose connection and a bit of corrosion on the wiring. The mechanic was really upfront about everything, showed me exactly what was wrong and fixed it right there. Total bill came to about €120, which included cleaning the connections and replacing a small section of damaged wiring. Such a relief it wasn't the entire sensor unit! Car's running great now, check engine light's gone, and the exhaust leak has completely stopped. The best part? Just did a quick emissions test and it passed with no problems. Really glad I asked here first, saved me from potentially spending way more than needed. Thanks again for sharing your experience, definitely helped me make a more informed decision!