Add the chicken to the slow cooker along with the mixture of the orange juice, lime juice, garlic, chili powder, cumin, oregano, salt and pepper and cook on low until tender, about 6-8 hours.
Pre-heat the oven to broil and move a rack to the top slot.
Shred the chicken, mix in 1/4 cup of the juices then spread it out in a single layer on a baking sheet and broil until it starts getting crispy, about 5 minutes. Mix in another 1/4 cup of the juices and mix everything up and broil again for another 5 minutes before mixing in another 1/4 cup of the juices.
Assemble the tacos on the tortillas with some sour cream, the chicken carnitas, and then top with Pico de. Gallo Serve with the lime wedges and add extra hot sauce or guacamole or shredded cheese if preferred.