In a medium bowl, combine olive oil, fresh lime juice, chili powder, ground cumin, smoked paprika, garlic powder, cayenne pepper, salt, and black pepper to create the marinade.
Place the chicken breasts in the marinade and coat thoroughly. Cover and refrigerate for at least 15 minutes.
Preheat the grill to medium-high heat.
Remove the chicken breasts from the marinade and grill for 6 to 7 minutes on each side or until the internal temperature reaches 165°F (74°C) and the chicken is cooked through.
Remove the chicken from the grill and let it rest for 5 minutes.
Slice the grilled chicken into thin strips.
Warm the corn tortillas on the grill for about 30 seconds on each side until pliable and slightly charred.
Assemble the tacos by placing sliced grilled chicken on each tortilla.
Top each taco with shredded green cabbage, diced red onion, chopped cilantro, sliced avocado, and crumbled cotija cheese.
Serve the tacos with lime wedges on the side for squeezing over the top.