Hey guys, thanks so much for all the helpful comments. Here is a little update:
So far all I have done is very roughly clean the whole area up. I scraped off as much as I could using a screwdriver and a toothbrush, got it all relatively clean so I can monitor for any changes. I then removed the 4 electrical connectors from the top of each injector to scrape off carbon buildup. While they were off i sprayed with electrical contact cleaner and put back in place.
I checked for a chuffing sound - didnt notice anything that sounded strange - perhaps did smell a bit of fumes, but again hard to tell. Took the car for a drive and maybe its just me, but It felt a little smoother to drive and i am almost positive my MPG is up... will be able to determine this better tomorrow with a trip to work and back. I know I haven't really done anything that should have made a difference but there does seem to be an improvement.
Next step - I am going to check the injectors every day to monitor for any buildup coming back.
I agree that it cant be the EGR causing that buildup, so will leave the EGR cleaning for another day and as will only remove injectors as a last resort.
Tommywho156 - from your instructions on removing the injectors, it seems very similar. There are little clips on the top of each of the 4 injectors. Just a quick question - does anyone know how I disconnect the fuel line?
With regards to carb cleaner spray - I bought some this evening in Halfords. All they had was this:
Halfords | Wynn's Fuel Injection & Carburettor Cleaner 500ml
I notice it says for petrol engines... is this safe to use? And do I literally just spray liberally over the whole area and allow to soak for a while? Will it then just dissolve off, or will it still be a bit of a job to rub of sticky black stuff?
regarding ERG and power being down a bit - I don't really know.. only had the car a few months, I have never noticed any problems with how it drives, but maybe performance was better before I got the car and problems arose...
Any more comments and opinions would be great, really appreciate the help so far!!