If I rememebr right you have either changed of tried MAF, Lambda, Plugs a Coil Packs.
The lamda is unlikley to be the cause as it is only used at idle and cruise, the MAF is used for fuelling above 0psi boost and/or 3000rpm.
Isn't the car already chipped as I recall you claiming 300BHP.
If it is chipped (not one of mine, AFAIK) then it may be the socket that the chip is fitted to is badly soldered or developed a dry joint.
I have seen Jap ECU with Prova and Mines chips/adaptors and the soldering could be done better by my 8 year old....nah..make it my 5 year old son.
Worth popping the ECU out and checking.
info on where it is and what to look for here :
http://www.polarperformance.co.uk/fitti ... tions.html
piccie here :
[img]http://www.polarperformance.co.uk/ecu.jpg[/img]