Mystery Misfire

[Phatt]

So about a month ago may car (E90 M3) started picking up a slight misfire on idle and between 2-3k rpm.It was intermittent once the car warmed up but every morning after standing overnight the car would misfire for about 20seconds during coldstart.

Wasnt worried about it much because the car ran smoothly when at operating temp. Then the car just went into limp mode with the check engine light.That was about 2 weeks ago.Since then the throttle actuators,coil packs,spark plugs,lambda sensors etc have been changed and the misfire persists.

Anyone else come across this? Help/advice is badly needed.