Chop the pork into 3 to 4-inch chunks. Place the pork shoulder in the slow cooker. Trim excess fat if needed, but leave some for flavor and moisture.
Sprinkle garlic powder, onion powder, salt, and black pepper evenly over the pork. Pour the Dr Pepper around the pork.
Cook on low for 6-8 hours or on high for 3-4 hours until the pork is tender and easily shreds with a fork.
Remove the pork from the slow cooker and shred it using two forks. Discard any large pieces of fat. Reserve 1 cup of the liquid from the slow cooker and discard the rest.
Return the shredded pork to the slow cooker and mix with barbecue sauce and the reserved cooking liquid until it is evenly coated.
Serve warm on buns, in tacos, or however you like your pulled pork.
