Excursion Diesel Power Loss and Smoke

Sounds familiar! I had the exact same thing happen with my old Audi A6, although it was a gasoline engine. Reduced power and smoke are classic signs of exhaust system issues. Have you tried forcing a DPF regeneration cycle? That might clear things up temporarily, but if the filter is truly defective, it's just a band-aid.

Interesting. I did try initiating a regeneration cycle through my OBD scanner, but it didn't seem to make a noticeable difference. How did you ultimately resolve the issue with your Audi? Was it a simple fix, or did you end up replacing the entire filter?

Yeah, a forced regen didn't do squat for me either. Eventually, the backpressure got so bad, the car was almost undriveable. I had to bite the bullet and replace the whole particulate filter. Not cheap, but it solved the problem instantly. Given your symptoms and the failed regeneration, I'd say it's time to take it to a shop and get it diagnosed properly. Could be other things, but DPF is the prime suspect.

Appreciate the insight. Sounds like I'm headed down the same path. Took it to my shop today and they confirmed it: DPF is toast. Quoted me 1550€ for a filter replacement. Ouch! But at least I know what the problem is now. Thanks again for sharing your experience!