Place pork roast in the slow cooker.
Pour soda and 1 cup of barbecue sauce over the pork.
Cover and cook on low for 8–10 hours.
Remove pork, let rest, then shred with forks.
Stir in the remaining 1 cup of BBQ sauce and a few spoonfuls of cooking liquid as needed.
Serve warm on rolls, in tacos, or however you like!