i have taken the earth tab directly under the battery tray off and cleaned it up, ive tried reseting the fuel cut off, only other bit's ive done are, removed jvc head unit, removed boot light bulb as well as the glove box light bulb!! no other bits have been disturbed. only other abnormal thing thats happened in the last couple of weeks was the alarm going off whilst car was parked in the drive, for no apparent reason. i dont believe i have any probs with the rev counter, as it is lit and works ok and i dont have the 'bulb' light on when driving.
finally, the code light does go off as normal, have even tried my spare key, to no avail.