I've got the same issue with mine mate. All I've done to mine is run a cold air pipe under the bumper sealing the box and a high flow filter. I've had the coil packs and plugs all tested and the fuel filter replaced and done the solenoid maintenance but still having no luck. I'm going to pull off the cat next week and check that out, with any luck it's just collapsed. I might pull the piping off my turbo too and check that its in tact. Let us know how you go with yours.