EGR blanks and Decat *should* be an instant fail.

However, mine passed with both missing

usually depends on one of a couple of things,
1, time of mot test Friday afternoon great time. Monday morning bad time.
2, cash in the ash tray, usually a £20 does the trick.
3, befriend mot tested in pub on Friday night, fill him with beer. Get new friend to test car on the saturday morning!

Egr valves are not covered under mot in England, nor are remaps. But I wouldnt expect this to stay this way for long unless we get out the eu soon.