Thanks for the responses guys, sorry I have been to busy to reply before now.
Right then! The car went in on Monday of last week to a dealer near my work as I didn't want to drive it 50 miles to the local dealer it was booked in with on the Tuesday morning. Limp mode was providing insufficient power to drive on a busy motorway safely.
They had it all last week and gave it back to me on Friday evening having changed HPFP (didn't fix the issue) and 1 of the injectors on cylinder 2 even though their checking tool gave 6 green lights.
I drove out of the forecourt and I don't think I made it 400 yards before splutter splutter, no power, limp mode. I took it straight back and I wasn't overly impressed but gave them the benefit of the doubt.
The worked on it again yesterday and found an air leak around the manifold so that replaced a few seals and wanted to keep it for an overnight test drive last night to make sure it was ok before giving it back again.
I should pick the car up later today and hope that its all fixed.
One thing as was unsure of though, is it common practice or should I say correct to change just one injector or should they not all be replaced with new? The other 5 have done 41,000 miles?
Thanks all