Heat oil in a large nonstick skillet over medium heat. Add garlic to pan; cook 1 minute, stirring frequently. Stir in chile powder and salt; cook 30 seconds, stirring constantly. Stir in 1/3 cup water and beans; bring to a boil. Reduce heat, and simmer 10 minutes. Remove from heat; stir in salsa. Partially mash bean mixture with a fork.
Warm tortillas according to package directions. Spoon 1/3 cup bean mixture into center of each tortilla. Top each serving with 2 1/2 tablespoons cheese, 1/4 cup tomato, 1/4 cup lettuce, 1 tablespoon onions, and 1 tablespoon sour cream; roll up.