Before you do anything, can we have some more information - is the car mapped at all?
Just stage 1 software, and an ITG enclosed Maxogen. The car has only shown the misfire twice - once with a flashing engine light and once without, it's been mapped for a while though and the 2 misfires have only happened recently. Plugs are probably 9k miles old now.
Move the coil pack to cylinder 1 and clear codes, if the code jumps to cylinder 1 then it'll likely to be the coilack at fault 
If not, swap just the spark plug and re-test.
Stupid question, are cylinders numbered 1-4 L-R or R-L? Ta.
I am also getting an issue with low fuel pressure, again it's under a load in a high gear (only really seems to do this in 4th, maybe 5th). Logs showed a difference between actual and requested, although I have not yet logged low pressure pump and high pressure pump, just rail pressure. I don't know if the two problems are related and will be starting with the fuel filter, followed by the fuel pressure sensor before moving onto the two pumps. Again this is a problem that occurred just before I decided to have the car mapped although it did have another intake (not as free flowing as the ITG either) which made me wonder if the airflow meant the turbo was producing more pressure than the pump could handle, but surely the stock HPFP can deliver enough fuel for a stage 1? Unless it's knackered.
