Still trying to solve this problem.
Had the car vagcom'd today with no faults stored?
I might try disconnecting the power supply to the tumble flap actuator tonight and see how it drives from cold in the morning! just to try and eliminate the tumble flaps as being at fault!
Just found this infomation below, Im now wondering if its something to do with that?
The 2.0L turbocharged engine operates in
two modes.
Cold Start Dual Injection
Dual injection is a special mode of operation
for rapid heating of the catalytic converter.
To do this, a quantity of fuel is injected on
the intake stroke at approximately 300˚
before TDC of ignition. The fuel distributes
itself homogenously due to the long gap
before ignition. The second injection occurs
at approximately 60˚ before TDC of ignition
during the compression phase.
The rich mixture that forms around the spark
plug means that timing can be retarded to
a considerable degree without affecting
engine stability.
Dual injection also achieves stoichiometric
(14.7:1) optimum air/fuel ratio. With the
exhaust valves open, the exhaust temperature
inceases rapidly bringing the catalytic
converter up to operating temperature 662°F
(350˚C) very quickly (30–40 seconds).
This is soooo difficult to diagnose