[Delboy]

Mmmmm .... any possibibility the pins have opened up a little on the connector plug that goes on that number 6 injector .
Could easily be a possibility

How does the injector seal at the bottom ...is it on a copper washer ? Any chance you have 'doubled up ' and left the old washer in the head ? These injectors are sealed with a teflon ring and therefore should sit and I fully believe it is sitting at the correct height.

Did you have to remove coil packs or plugs ? Something disturbed there ?
Yes they have been off a few times in my ownership, as this cylinder 6 has had intermittent misfires for a while now.

Can you feel it missing like a dropped cylinder , worth putting a vac gauge on the manifold to see if any pulsing .....thinking possibly the clean on the valves have dried the guide and valve stem out and valve sticking in guide somewhat , bit of a long shot but I'm just throwing ideas in.
Certainly shouldn't rule this out but the misfires are so infrequent that I would think it's not that.

A vacuum gauge is one thing I don't have at my disposal at the moment.

I do have a compression tester and I done a compression test on all the cylinders prior to the carbon clean and they all came back good, despite that I still had the odd misfire.

I also put a full set of new plugs in her, and moved coils around to see if the problem moved, which it doesn't.

I was messing around with VCDS yesterday and cleared out all the fault codes from the car after all the work i had done and I thought it felt better than after a run the other night.

So i'm wondering if there is some other issues with something like 02 sensors, or something else that once the trims start to take effect the misfire becomes more prominent???

For now though I think I ought to check out the coil pack wiring as you mentioned because thats been disturbed the most lately.

I'll record a video of the misfire counters and upload here so you can see what I'm taking about.

Thanks