Qashqai diesel particulate filter issue

Whoa, reduced power and smoke? Sounds rough! I had similar symptoms on my old Astra – turned out the DPF was totally clogged. Have you tried forcing a regeneration? Sometimes a good long drive at a constant speed can burn off the soot. What kind of driving do you usually do – lots of short trips?

I haven't tried forcing a regeneration, to be honest. Most of my driving is city driving, short trips to and from work, so that probably isn't helping. How would I go about initiating that regeneration, and is there anything else I should be looking at? I'm not very technically minded.

Okay, city driving is a DPF killer, sadly. Forced regeneration sometimes requires diagnostic software – which most home users don't have. Given the symptoms and your driving style, plus the fact you aren’t confident with the tech side, my gut says your DPF is likely toast. Get it inspected by a workshop before doing anything else! A blocked DPF can cause serious damage if ignored. I had to get a new one installed on my old car, and it was pretty pricey. Think you'll have to spend around 1550€.

Thanks for the advice. Sounds like a trip to the workshop is in order. I suspected it was the DPF, but your input confirms it. Will get it checked out. The workshop confirmed that the diesel particulate filter was indeed defective, and they're replacing it as we speak.