Johnson started racing motorcycles in 1980 when he was four. Three years later, he won the 60cc class championship, despite having an injured knee. Afterward, he moved to the Mickey Thompson Entertainment Group (MTEG) Stadium Racing Series where he won several more awards.
In 1993, Johnson was given the opportunity to drive for Herb Fishel. He refused the deal and continued racing buggies and trucks in off-road stadium and desert races. He also reported for ESPN in the Short Course Off-Road Drivers Association (SODA). Three years later, Johnson drove for Herzog Motorsports in the off-road truck series in 1996. By 1997, Johnson had progressed to SODA's Class 8; Class 8 is short-course off-road racing's class of two-wheel trophy trucks which generate about 800 horsepower.
He battled Scott Taylor and Brendan Gaughan for the championship. That year, Johnson won both races at Lake Geneva Raceway's first race weekend in May. He also won the season's third event at Antigo before finishing second to Brendan Gaughan at Antigo's second race.
Johnson returned to Lake Geneva in July, winning the Saturday race and finished 2nd on the following day. Taylor ended up winning the championship with Gaughan second and Johnson third. During his time in the SODA, SCORE and MTEG series, he accumulated over 25 wins, 100 top-three finishes, six championships, and received Rookie of the Year honors in all three leagues.