1. In a mixing bowl, combine chili powder, cumin, garlic powder, and salt.
2. Rub the spice mixture onto the fish fillets.
3. Heat olive oil in a skillet over medium heat. Cook the fish for about 3-4 minutes on each side until cooked through.
4. Warm the corn tortillas in a separate skillet or microwave.
5. Assemble the tacos by placing pieces of fish on each tortilla. Top with shredded cabbage, pico de gallo, and chopped cilantro. Serve with lime wedges.