Just a little update.
Had the new EGR valve fitted on friday, but vxl told me although the problem with the EGR had been cured the ECU was still buggered and need replacing or fixing, and that this might still cause the misfire. Got in the car and drove off, it did feel better but there were times when it was playing up, just wanted to get rid of it tbh. For 2 days it was misfiring, yesterday and today its been running perfect and even had the chance to floor it and feel the benifit of no pre cat, for the first time in over a week ive actually smiled while driving it.... so fingers crossed its now back to normal! I think what happened was that the old EGR was causing the misfire and the ECU was registering that, so when the new one fitted the ECU was still thinking it was broke and took a few days to adjust! I just hope this is the end of it!!!