Is it only @ cold start?
Either way I wouldn't make a big deal out of it unless you have other issues that follow
Black smoke would be a rich mixture
Depending on the combination of climate and type of fuel your using can be a contributor
You should probably turn the adjustment needle in one full turn on the carburetor to lean it out some. Or make sure there is not excessive grease on the muffler bearings. Orrr just listen to kneegradamus he is probably more accurate.
Ok -4.. Wow f that. Noooo thank you.. Lol
Either way I would not worry about it
I would say giving the temperatures and the fact we are dealing with direct injection, it's seems quite normal to me.
Cold start as it is with a DI is going to run richer for a short period of time, and with the addition of colder temperatures the mixture will be even richer for a short period of time until cylinder temperatures get up to normal. Even further more we run rich from the gate
Some black smoke at cold start and wot is pretty typical. Cold start because it is dumping fuel to get the cat up to temp. The Wot stuff is just because it runs super rich and is more of a soot then anything