In a large microwave-safe bowl, mix cereal and pecans. In a 2-cup glass measuring cup, combine brown sugar, butter, corn syrup and salt; microwave, uncovered, on high for 1-2 minutes or until smooth, stirring once.
Whisk in baking soda. Pour over cereal mixture, toss to coat. Microwave, uncovered, on high 3 minutes, stirring every minute.
Spread onto a parchment paper-lined baking sheet; immediately sprinkle with chocolate chips and caramel bits (do not stir). Refrigerate until chocolate is set. Break into pieces. Stir in pretzels. Store in an airtight container.