Stumbled across a link for some useful info for the 1.9JTD inlet manifold, and a possible explanation for misfiring and MCSF errors.
The Z19DTH engine is used in also used in recent Vauxhalls and SAABs
to inlet manifold document.
I'm getting a P2013 error after a long(ish) run only. If I only drove round town all day, apart from the occasional misfire, I'd never know there was a problem. My Indie has suggested the manifold/valves/actuator may be the problem. Booked in to be looked at.
According to eLearn the timing belt/inlet cam has to come off to remove the inlet manifold, although posts in the Vectra Forum
(see post #22) suggest it's possible without removal. Although of course there may be subtle differences between the Alfa/Vauxhall unit.
All the best