Stir 1/2 cup salsa, chicken, pepper and avocado in a large bowl. Stir the remaining salsa and sour cream in a small bowl.
Spread 1/4 cup sour cream mixture onto each tortilla to within 1/2 inch of the edge. Top each with 1 cup chicken mixture and 1/2 cup lettuce. Fold the sides of the tortillas over the filling and then fold up the ends to enclose the filling. Cut each wrap in half before serving.