Place oil in removable pan of programmable pressure cooker. Place pan in pressure cooker. Using sauté function, heat oil until hot. Add turkey and onion. Cook, uncovered, about 5 minutes, or until turkey is no longer pink, stirring to break up. Press cancel.
Stir in beans, tomato sauce, diced tomatoes, broth, chili powder, garlic salt and pepper. Stir in macaroni. Secure lid and set pressure release to sealing function. Select high pressure setting and cook 5 minutes. Allow pressure to release naturally for 2 minutes. Move pressure release to venting function to release any remaining steam.
Remove lid. Stir macaroni mixture. Whisk together milk and flour. Stir into macaroni mixture. Using sauté function, cook and stir, uncovered, 1-2 minutes, or until boiling. Press cancel.
Stir cheese into macaroni mixture until melted. Ladle into serving bowls. Spoon dollops of yogurt or sour cream on top.