Not my 2.2........but neighbours veccyC 2.0 diesel on a 53 plate.
First thing in the mornings it had started to take upto 15secs of cranking before starting when its quite cold....then would pop on EML for about 10secs then go off.
As i carnt read a veccyC ecu.......he took it to vx dealer for diagnosis.......they read the codes......and told him there all 'not present' codes (tho didnt tell which ones they were) and then told him.....they were 99% certain its the glow plugs.
So yesterday vx dealer changed em all.......at a cost of about £150

This morning it did start on the button

(but maybe it did coz it was warmer this morning).......but when driving around EML kept coming on and going off.......something its not done before.......so he took it back.......vx dealer found a connecter they hadnt reconnected 'so they say' and all will be fine now......well it wasnt and EML kept coming on.....so he took it back again......
This time diagnosis was.....its the MAF sensor.......and they wanted £140 plus labour to change it.......he argued with them.....that there wasnt anything wrong with it before they changed the glow plugs.......in the end vx dealer did him a 'deal'.......£106 including fitting.......so he let vx dealer change it.......
Just phoned him now.......and guess........yep.....EML is back on permanently now......vectra isnt running right.....

He isnt a happy bunny........ive told him to go back to vx dealer in the morning and ask them to refit the old MAF sensor as obviously theres nothing wrong with it.....and get a refund.
Case of vx dealer randomly changing parts to try to fix the fault?? :-/
You decide!!