[size=14] I have just found my exhaust manifold cracked. OK i admit i did not believe members who told me to double check. My car is the later 2.2 litre engined car, is the manifold the same as the early 2.0 litre cars the engines look the same 4 cylinder Eco engines. Because there are very few 2.2 cars being broken but lots of 2,0 litre ones
Also there are two studs snapped, has any one had any luck drilling them out in situ, plus do you think the cracked exhaust manifold could be my rough idle problem cheers bash[/size]
You need to sort your manifold problem first before your idle problem as a cracked manifold and nuts/studs not sealing against the cylinder head will certainly not help your problem with the idling.
There are some 2.2's being broken out there but you would probably need a more 'specialist' late Vauxhall breaker to have more chance of finding what you need. I don't know what is near Doncaster area but in Notts/Derbys there is
http://www.megavaux.co.uk near Nottingham (just off J25 M1) they have a good website which lists all the Omega's they have in including several 2.2's. I have not tried them myself yet but I am going to try them for a cat for mine. The only problem with a used one is finding a good one as this is a common fault unfortunately. A new one from Vx is approx £100+ VAT on TC I think.
The snapping of the studs is also common which I experienced myself and yes it has to be the one near no.1 cylinder right at the front which is a real bs'tard to do. Fortunately, there was enough thread in the head to re-use so hopefully this will hold. Several members with 2.2's (and 2.0's) have also found 'bodged in' studs where previous 'messers' have made a bodge job of it, so you are not on your own!
Get this sorted first and then see what idle problems you have afterwards and if you still have no joy, as I said before try Marks_DTM Calib as he maybe able to help!
Good luck!

Dan