In a skillet, heat the olive oil over medium heat. Add the shredded chicken, chili powder, cumin, garlic powder, onion powder, salt, and black pepper. Stir to combine and cook for about 5 minutes until heated through.
While the chicken is warming, warm the corn tortillas in a separate skillet over medium heat for about 30 seconds on each side until pliable.
Assemble the tacos by placing a portion of the seasoned chicken on each tortilla.
Top with diced tomatoes, shredded lettuce, diced red onion, and chopped cilantro.
Serve with lime wedges on the side and a dollop of sour cream if desired.