Mix together the salt, pepper, coke zero, and brown sugar. You can place the roast with this marinade into the crockpot or gallon size bag and let it marinate overnight or for at least two hours.
Take the pork out of the fridge and add 1/4 cup water to the marinade. Cook on low 4-6 hours or high 3-4. The pork should be able to shred very easily with fork.
Drain all liquids and shred the pork with two forks. Mix ingredients for step 2. The coke zero, green chilies, tomato sauce, chipotle chili, garlic powder, cumin, chipotle chili powder, brown sugar, and salt and pepper to taste. Mix with the shredded pork and continue cooking for an hour.
You can serve with black beans, cilantro lime rice, or whatever your heart desires. :)