Slightly break up the Fritos in the bag and put them in a 9X13 pan. Heat sugar and Karo in a saucepan and cook until warm and sugar is disolved but don't boil. Take off heat and stir in peanut butter and pour evenly over Fritos. Sprinkle chocolate chips over the top and let them soften. Let stand over night or if you can't wait, put them in the fridge for about 15 minutes and cut in squares.