Zafira Engine Management Problem

Have a 2003 Zafira (out of warranty). Last weekend noticed some odd
things going on when accelerating - a slight, brief, but noticable
reduction in power when accelerating, normally at the higher end
3000-4500rpm. 24hrs later the Engine Management light came on.
Later realised, on subsequent mornings that a cold start was unusual -
immediately after the engine fires up, the revs climb higher than they
normally would, perhaps past 2000rpm, before settling down to a normal
1100rpm. Then I try pulling away while still cold and there's very
little pulling power, as if its about to stall. Push the clutch down
and the revs will go back to 1100 and have to rev excessively to ensure
it pulls away. When warm starting, no symptoms.
The reduction in power when accelerating is still apparent.
Engine Management light comes and goes.
Anyone any ideas before I take it to the garage? Sensor, blocked pipe,
something simple?

 

MAF mass air flow sensor
and
ICV idle control valve
and
good dose of carb cleaner

would be my first ports of call if it has not been serviced recently.

though it could be many things.

EGR valve could be the culprit too.

mike