Preheat oven to 350°F. Combine flour, baking soda and salt, stirring with a whisk to blend. Beat sugar and butter with mixer for about 1 minute at medium speed. Add banana, egg substitute and yogurt, beat until blended. Add flour mixture, beating at low speed just until moist. Melt chocolate chips in microwave until smooth. Cool slightly. Add 1 cup batter to chocolate, stirring until well combined. Spoon chocolate batter alternatively with plain batter into a loaf pan. Swirl batters together using a knife. Bake at 350°F for 1 hour and 15 minutes or until wooden toothpick comes out clean. Cool 10 minutes on wire rack in pan then remove from pan. Cool completely on wire rack.