still chasing my rough idle, misfire. dumb question.
 

Hi, so I still have vibration at idle. idle rpm is stable and no error codes but after a few months of no issue, yesterday the car was misfiring. I turned it off and back on again, and the misfire went away right away. I wonder if that is a clue.

anyway, I have a smoke detector from Amazon... I have not used it yet. my dumb question is this. if there is no leak in the system, where will the smoke come out of after some time letting it run?

I already changed my valve cover gasket, my disa valve, the rubber elbow. at this point I'm sure it's the ccv or vac lines, or my MAF.

thanks.

How many miles on this m54? If ccv and vacuum lines have never been done, they are likely due. Watch out for the dip stick tube iring as that is a commonly overlooked source of vac leak. Good luck random misfires suck to diag sometimes, smoke machine is good idea too.

thanks. main question. if the ccv and vac lines are not the fault, where will the smoke exit from?

Through the CCV system into the intake to get burned during combustion.

car is off while smoke testing. so not burned during combustion.