As much as i dislike GM products, their top engine cleaner works wonders and is easily available. I give the ecoboost motors a whiff of it mixed with seafoam every 2nd oil change. Keeps the deposits down. I actually had a farm fleet bring me their vehicles after they were tired of the dealer giving them the runaround about a cold start misfire in their trucks.
gm part 88861803. available at any good parts retailer or gm dealership. run 2 oz mixed with a can of seafoam ever 12-15K on a direct injected engine. I suck it through the vacuum port right behind the throttle body on my SHO. Do this on a hot engine, shut it down after sucking it through slowly. let it sit for 15 min and take it for a blast.
