I had the same problem after fitting a prototype intake about 2 years ago. I got an AFC and that solved the problem for about 18 months. About 3 months ago it came back with or without the AFCs help, and ECU resets only lasted for 50 miles or so. I found that adding FI cleaner seemed to help briefly, but not for long. I have platinum plugs with less than 5000 I think, so I don't suspect them. I may try the Knock Sensor mod. This car certainly is a piece of work, just about as tuned as an old 60s muscle car. Hopefully with the turbo and TECII there will be better control over it, though I doubt much less work!