Corsa diesel power loss and smoke

Greetings. I experienced comparable symptoms with my 2012 Peugeot 308, also a diesel. Have you attempted a forced regeneration of the DPF? What is the status of the differential pressure sensor?

Regeneration? Not yet, no. Where is the sensor usually located?

On my Peugeot, the differential pressure sensor was situated near the DPF itself. However, given the mileage and symptoms, a blocked or defective DPF is highly probable. It would be prudent to seek professional diagnostics; the filter replacement will be expensive, but the damage arising from a defective DPF is more expensive still.

Thanks. Took it to a local garage; DPF was indeed the problem. Replaced it, cost 1550€. Runs like a dream now.