2009 330i - Initial misfire on cylinder 3 only

[pp599]

Hi Guys

I am hoping somebody here will be able to help me out. I've recently bought a 2009 330i about 4 months ago. Not soon after I seem to have a few problems with the engine. When I first start the car I can feel the car misfiring and the CEL comes on after a minute or so. Then after about 5 minutes the misfiring seems to stop and the CEL goes off.

The engine also has no problem whenever I start up the engine later on the same day, the problem only exists on the first start up of the day.

I have also noticed that the CEL is not there on start up on a warm day, even though I can feel a few misfires but they are just not as violent/often.

I've had the car taken into a garage and the fault codes that have come up are

1) Misfire on cylinder 3
2) 30E9 - Nitrogen-oxide catalytic converter, ageing

Since then I have replaced everything on cylinder 3 (injector, decoupling element, sparkplug) but unfortunately the same problem is still there.


Here's a video of the issue I have at start up.

[Helmsman]

Might want to post this on a specific 330 site (rather than M3)?

Cheers