I agree you didnt say anything about the misfires - i did in my first post Reason being it did have misfires on all cylinders before i cleared them along with the o2 codes.

ok - how do i go about finding if the mixture fault is lean or rich, idle or under load?

I'll check the elbow I know exactly which one you mean because when i changed the ccv (oil sep) recently i had to remove all the air intake tubing and throttle body (not the intake manifold method though) - could it be that i done something on refit like not seated the gaskets? I was a little unsure which way the rubber gasket faced near to the maf because it did not have an obvious channel for the ribs to sit in.