Having the same issue, don't want to open a new thread. My car has 113,000 km on it (70k miles) and the past week the weather got colder and I'm starting to have some problems on cold starts.
I'm thinking of replacing all 6 Injector/Coils/Spark plugs. is that a good idea? or is it better to let the dealer check which ones are faulty? the car doesn't show any lights/faults, so not sure if they will find anything.
Also I've asked the dealer about intake valve cleaning and they said it is a big job they to remove the head or something, so that's going to cost alot. is it OK to do the replacements, without doing the cleaning?