Hi

I wonder if anyone can help. This Astra keeps going into limp mode with p0400 (egr insufficient flow) flagging up. Cycle the ignition it runs again fine. It happens at idle or at revs. The egr valve is vacuum operated and holds a vacuum. As does other vacuum operated devices. The solenoid switches. The vacuum pump appears a bit weak at 18inhg and takes a while at idle to get there. Vacuum at egr valve is around 14inhg.Boost sensor is reading 14-19psi between idle and stationary full throttle. Air flow is 485-640mg/strk at the same points.

Any help welcome.