In 2002, Childress hired Sauter to run a full Busch Series schedule in the No. 2 AC Delco-sponsored Chevrolet. He notched five Top 10 finishes, including his first Busch Series win in the Tropicana Twister 300 at the Chicagoland Speedway, despite skipping one race. Sauter was involved in one of the biggest accidents in NASCAR history in the Aaron's 312 at Talladega, where 33 of 43 cars were involved, and 15 of them were taken out of the race. In 2003, Sauter drove for Childress Racing and the Curb Agajanian Performance Group in the Busch Series, piloting the No. 21 PayDay-sponsored Chevrolet and the No. 43 Channellock/Curb Records-sponsored Chevrolet. He captured 14 Top 10 finishes in 34 Busch Series starts, including a win at Richmond in the No. 43. Sauter finished the 2003 season eighth in the driver standings and, together with Kevin Harvick, led the No. 21 car to the owners' points championship.