DPF and AdBlue Issues Plague Infiniti EX Diesel

Hey there! I had a similar issue with my 2015 Infiniti QX50 diesel (pretty close to your EX). I've got some experience working on cars, but mostly basic maintenance stuff. My car showed similar symptoms last year check engine light, DPF issues, and Ad-Blue warnings. After taking it to my trusted workshop, they diagnosed a faulty Ad-Blue tank that was causing system pressure problems. The fix wasn't cheap set me back about 1620€ including parts and labor, but it solved all the issues at once. What's your mileage and have you noticed any other symptoms? Also, when was the last time you had the Ad-Blue system serviced? This info would help me share more relevant details from my experience.

Thanks for the info! My mileage is currently at 169757 KM, and the last service was about 3 months ago. I've also noticed the engine seems a bit rougher when idling, especially in the morning. The Ad-Blue tank still shows it's nearly full on the dash display, which makes me wonder if it's actually a sensor issue rather than a tank problem. Did you get any error codes before getting yours fixed?

Hey again! Thanks for the additional details. Yeah, those symptoms sound very familiar my QX50 was doing the exact same thing around 175,000 KM. The rough idling in the morning was definitely something I experienced too! Interestingly, my Ad-Blue tank display was also showing nearly full when I had the issue. That's actually what threw me off initially. But here's the thing I did get error codes (P20EE and P208E) which pointed to the Ad-Blue system, but it turned out that the sensor was indeed the culprit, not the tank itself! My mechanic found that the Ad-Blue quality sensor was faulty, which was much cheaper to fix than replacing the whole tank like I mentioned before. Looking back, I should've mentioned this in my first reply sorry about that! The sensor replacement cost me around 380€ including labor, way less than what I initially quoted for the tank replacement. Since your symptoms are so similar to what I experienced, especially with the full tank reading, I'd bet you're dealing with the same sensor issue. Have you noticed any decrease in power when accelerating? That was another symptom I had that I forgot to mention earlier. If you're experiencing that too, it would pretty much confirm my suspicion about the sensor. Hope this helps clarify things a bit more! Let me know if you need any other details about my experience with this.

Thanks so much for the detailed follow-up! Actually, yes I have noticed some power loss during acceleration, especially when merging onto highways. You've just saved me a potential headache and probably quite a bit of money too! I'll definitely have my mechanic check the Ad-Blue quality sensor first before looking into more expensive repairs. The error codes you mentioned will be really helpful for diagnosis. Really appreciate you sharing your experience it's given me a much clearer direction on what to check first. I'll update the thread once I get it looked at, might help others with similar issues in the future!