In his final three seasons he was a member of a team that placed among the nation's top-ten in total defense. Johnson also excelled on special teams as a punt return specialist. Many of his punt return marks still stand in the UT record books. In his freshman year, Johnson got off to a great start being named a starter in his first game, but a leg injury kept him on the sidelines for much of the year. The next year, he regained his starting status on a team that went through the regular season undefeated. That year his fourth-down tackle inside the Texas five-yard line preserved a win over Oklahoma. He won the first of three All-Southwest Conference honors that year. In an era before the advent of the Thorpe Award, Johnson was named the nation's top defensive back of 1978 by the New York Downtown Athletic Club.
Johnson holds the Rams record for the longest interception return after scoring on a 99-yard return against the Green Bay Packers in 1980. Off the field, he appeared in the 1986 Rams promotional video, Let's Ram It.