Seriously Happy Now but its been a long road
Well after all of the above problems, i got around to taking the car back to Seat Bristol as everyone seemed to be telling me that it was the MAF.
After running tests it was decided that Seat would require the car returned to stock in order to investigate the fault code problems. Initially they were happy to do this but after speaking to Will at Performance Torque were not afraid to admit that they were out of their league and as such were not confident in flashing the ecu back to stock.
At this point i must say a big thank you to all at Bristol Seat, who were supportive throughout and most importantly did not charge for the diagnosis even though it was inconclusive.
But a much bigger thanks must go to Will at Performance Torque, who suggested that it could all be down to the massive reduction in back pressure caused by the new down-pipe and sports cat.
Basically it appears that the turbo was spinning up much faster than the ecu was planning for so it was having to dump extra fuel in to compensate and the problems spiraled from there.
A custom map was all it took solve the
problem and bring the timing pull back to 1.5. Will was also able to slightly dial out the low rev boost in the lower gears so the car no longer wants to rip my head off just for blowing on the accelerator.
I now have a car which seems much more progressive. I know we all love the turbo surge, but mine was quite extreme (3rd gear was hard work in the wet!!) and made it difficult to drive smoothly.
I will give it a while and report further once i have gotten used to how the car is driving with its new map.
The main thing is that with the timing and fueling sorted, the car will now pass an emissions test.
Thanks to every one who offered their advice on this matter.
Matt