Ive been looking into the parts etc that cause the common problem of dropping revs when aproaching junctions etc, and have found out some things that some may or maynot know
When people say there isnt an ICV (idle Control Valve) on the astra i thought how on earth does it know how the car is idling then??? turns out the ICV does exist but its a physical part of the TB, and there fore the reason why vauxhall change the TB when this problem occurs!
Other thing is also, (after Jam informed me and i looked into it a bit) the 'engine temp sensor', which i believe is located on the inlet manifold, but on my autodata says on the manifold there is a 'intake manifold air control solenoid', which sounds like it could cause a problem with revs as it controls incoming air, (obviously ) so i may try replacing this to see if it cures the problem
Ive replaced the EGR valve which helped alot, and highly recomend replacing it over cleaning it,
just to let people know my progress, although im temped just to buy a dam new TB!!!!!