Hi guys got this Zafira, first start is fine will drive like a dream. randomly when you turn off engine and restart it will not rev up that well, if you give it a boot full it will clear and drive fine again, code P2279 will be stored when it wont rev up straight away.
Parts Fitted.
EGR Valve
Throttle body ( All Genuine )
Turbo
Mass Air Flow

Dpf Pressure is 0.2 kpa, saturation is 2%
What i notice is MAF is 44-45 kpa when running well, but gets pulled down to 18kpa when it wont rev, Pipes and manifold have been smoke tested, pipe work and manifold removed and checked for blockages.Inter cooler by passed to check it wasn't blocked. Complete exhaust and dpf removed just to double check no blockages, same thing happens........

Any Help would be appreciated.