Palio diesel power loss smoke

Sounds familiar. I had similar symptoms with my old Opel Astra, though it was a gasoline engine, not diesel. Reduced power and smoke were the key indicators. In my case, it turned out to be excessive backpressure in the exhaust system, probably due to a clogged catalytic converter. Have you checked the backpressure? It might be worthwhile to rule out any sensor issues related to the exhaust system before jumping to conclusions about the DPF itself. How old is your DPF?

Thanks for the insight! I haven't checked the backpressure directly. How did you go about checking it on your Astra? And regarding the DPF age, as far as I know, it's the original one, so it's been in use for the entire life of the car. Do you think a simple vehicle inspection would be sufficient, or is there a more specific test I should request?

On my Astra, a mechanic checked the backpressure with a gauge connected to the exhaust system. Given that your DPF is original and the car is 20 years old, it's very likely the filter is clogged or defective. If you have the original DPF, it is probably at the end of its life. I'd recommend taking it to a workshop for a proper diagnostic check. They should be able to confirm the DPF issue and give you a quote for a replacement.

Thanks a lot for your help! I took it to a local workshop, and they confirmed that the DPF was indeed defective. The final repair cost, including filter replacement, came to around 1550€. Hopefully, this will solve the problem for good.