Just got the car back from Hi tec complete with graphs; everything looks pretty smooth. The fuelling has been altered and the car went like a rocket......until it started spluttering again. Pretty sure Oakmere's right, something dosn't sound sealed, it sounds flappy if that makes sense. I'll take it off and refit again this weekend making sure everything's sealed properly.
If anyone wants to see the graphs they are pretty poor quality but I can try scanning them in. I'll have to email as I havent a clue how to post images up.