OK found it - regeneration valve is the same item as the tank vent valve.
I have already replaced this item, looks exactly the same as the item fitted to a lot of Audi's except the Porsche item has a fitted moulded pipe hence double the price!
Bosch manufactured part, could easily adapt the pipe to fit, it would save a lot of hassle trying to remove the aforementioned "P" clip on the inlet manifold.
Will also replace the fuel filter on my next visit, just for the sake of eliminating another item.
Merry Xmas Bugman:
