came into us via 3 other garages, showing missfire cylinder 1 and cat damaging misfire cylinder 1
It will only misfire after it is hot and done around 10 - 15 miles, then the miss will continue ( ecu cutting out injector ? )and only ever on cylinder 1 and there is never any other faults to go with it.

It has previously had a set of genuine merc coil packs,and a new air mass meter ( merc again )
I have replaced the coil pack loom due to an insane amount of punctures where someone had been cutting it open to test continuity i guess.
While I was at it I swapped injector cyl 1 with injector cylinder 2 but the problem still persists.
I have scoped coil primarys , air mass and injectors and all seems well but 15 miles later ...
I'm running out of hair to pull out