2002 vectra 2.2 dti p0400-f8 egr feedback signal code

[robbocop33]

So, very rarely engine check light will come on accompanied by slight loss of power, probably some kind of limp home condition.
Anyway egr valve is completely cleaned and free moving. I used my bidirectional scan tool and commanded the egr to close and open, this worked well so wiring good, but, randomly sometimes i would command the egr open to 100%,then when i tried to command it closed it would stick at 100%??
This would be cured by a slight blip of the throttle! Then it would close, anyone any ideas? I'm thinking faulty solenoid maybe?
Car idles fine and drives (albeit underpowered) , even when engine check light comes on, no stalling etc.

[GreenV8S]

Since you seem to be able to reproduce the problem, I'd start by trying to work out whether it is an electrical problem outside of the solenoid or something inside the solenoid. You could back-probe the connectors at the solenoid and see whether it is getting the usual electrical signals when the problem occurs.