ive done afew of these lately at work, ive found its the loom plug to the ecu(with nasty metal cover) i think its the left hand one. when you remove it from the ecu the glue inside the plug seems to melt and you get a bad connection. when you remove the plug look at the ecu pins. if there covered in glue/silicon deposits that could be the prob. seems to be very common when it come up with a pedal/ throttle body track1/2 code. we just change the engine loom which costs about £175 but you mite be able to clean it up. they are fussy with spark plugs and the gap, coil pack etc etc i could go on! try the ecu plug tho!