So the Saga continues, it's a MAF issue. I ended up not getting a genuine MAF sensor that I got from Ebay. The engine had a really rough idle and the whole car was shaking. I plugged the MAF and it ran smooth again.

Just to check I turned off the car and started it again without the MAF plugged in and the car ran fine. Plugged it back in and ran rough.

I'll be buying a BOSCHE MAF sensor very soon. Sad to think all this time I've possibly been only driving my car at half power!

According to Torque Pro the MAF is only reading 140g/sec of air at WOT. I may be wrong but I think it's supposed to be over 200.