He was a star there for two years, leading the team to the NJCAA national tournament in the 1976–77 season while averaging 29 points per game and being named a junior college All-American.

Johnson earned the nickname "the Microwave" from Boston Celtics guard Danny Ainge for his ability to heat up an offense by scoring both fast and frequently when inserted into the game.

[2][5] On June 14, 1990, Johnson made a championship-clinching 14-foot shot with 0.7 seconds left to beat the Portland Trail Blazers 92–90 in Game 5 of the NBA Finals.

The Pistons honored Johnson's career by retiring his number 15 jersey in a ceremony on February 5, 1994, at The Palace of Auburn Hills.

[2] Johnson was influenced by New York City playground legend and basketball Hall of Famer Earl Monroe growing up, and only wore number 15 throughout his playing days.

[7] In addition to his post-playing career professional work, Johnson is a member of the Michigan Minority Business Development Council, and the Detroit Chamber of Commerce.