Well my 56 plate Zafira started losing power and the diagnosis went from a air mass sensor to ecm.
In the end the fault was a clogged up Diesel Particulate filter, I sensed saving some money after hearing the word filter compared to the Air mass sensor or new ECM until I rang the dealer and found it costs over £800.
If you have a diesal and only do town runs you need to drive it hard at least once every two months otherwise like me you will have an expensive lesson
Wish I had know this before