Well yesterday the noise I had been describing came back with a vengence...however the garage today discovered 3 codes had been logged, as the car is now running smoothly and no loss of power.
Injector 6, knock sensor - bank 1 and crankshaft sensor - all indicating voltage drop problems.
So the conclusion the garage have come to is when the car landed with a thump that dislodged a connector(s) - had this before with the damp on the crankshaft sensor and it is a known prob with the x25xe.
So its going to be manifold off and check every connection (WD40 on each).
Of course I will be blanking the EGR and refitting the Bosch Super 4's
Also had a coolant leak from top hose when under pressure that was spraying coolant on to the air filter but that's down to those standard clips which I will change to a screw type - so a filter clean will also be needed.