Polo flutter issue when starting

[Jack0420]

Hi everyone, I wonder if someone can help. On startup, specifically when the car has been left overnight, my engine flutters and grumbles, only until I wait a few seconds or rev. See video. When opening the engine cover, there is also white smoke from the back portion of the engine. You can also smell a burnt diesel smell. The maf sensor is good but the oxygen sensor is full of soot. Any ideas? It is a 1.6tdi polo mk8