2. In a mixing bowl, toss the shrimp with olive oil, chili powder, salt, and black pepper.
3. Grill the shrimp for 2-3 minutes on each side until they are opaque and cooked through.
4. Warm the taco shells on the grill for about 1 minute on each side.
5. Assemble the tacos by placing grilled shrimp in each shell, then topping with shredded cabbage, a dollop of sour cream, chopped cilantro, and a squeeze of lime.