My understanding is that excessive heat (unburnt fuel) will damage the cats over a period of time.
Well, it got thru last year, and hasn't done many miles. So, probably OK...
As a matter of interest, how far is the MOT centre from you house and did they MOT the car as soon as it arrive - or was it left to cool and then the MOT'd?
I have a car that reads high unless it has been given a good run and not allowed to cool down before the MOT.
About 15/20mins - with traffic at the end, so it had the electric fan cutting in before it got laid up. It was being emissions tested an hour after it arrived - since I turned up to collect it at that point
So, although it could've been made a bit hotter (ie done emissions immediately) there was no starting from cold.
