TYPICAL!
Just called the garage to see how the truck had done and they said that the auxiliary belt tensioner had given up the ghost in the last 3/4 of the emissions test.
Gonna drop round tomorrow morn with a new belt and tensioner from the spares truck (which has already paid for itself).
The good news is everything else had passed and the emissions were looking good until the tensioner let go
It appears that the 2 things my truck likes to eat are starter motors and aux belt tensioners.
5 starters and this will be my 4th tensioner in 7 years of ownership.