Hey! Yep we will change all of the above, we had a boost gauge on it today and it's when it gets to maximum boost that's when it misfires. If you keep the boost below max it doesn't happen. Also engine light is completely off as doesn't even come on when I put ignition on. Thank you so much for all comments. I will let you know how I get on. I also have a coolant leak, it seems as though the expansion vessel fills up and overflows and radiator is loosing fluid (strange) xx