Hi all. I'm new to fordsnation so i need a little help getting around. I bought a second hand 2014 focus st with 57k miles on the clock. running amazing but throwing a puff of black/blue smoke on startup and stutters for 2 seconds. No smoke when i drive it hard. Only on startup. And if it sat for a few minutes it happens again. stutters for 2 seconds, throws a puff of black/blue smoke and then everything is normal after that. no smoke on WOT. If you can point me in the right direction i will appreciate it allot. And Thanks in advance ?