After a long karting career spanning between 1986 and 1993 Larsson debuted in single seaters in 1994. Larsson dominated the Swedish Formula Ford Junior category winning eight out of ten races. At eighteen years old Larsson debuted in the Barber Dodge Pro Series in the United States of America. In his first season the young Swede won the race at Texas World Speedway and scored another three podium finishes. These good results placed him fifth in the championship standings. Larsson returned to the series in 1996. After winning five races in the twelve round season Larsson only had to finish twelfth in the last round to secure the championship. At Lime Rock Park the Swede finished second and secured the championship while Derek Hill won the race. After his championship win Larsson graduated into the Indy Lights. Larsson drove his Lola T97/20 entered by Johansson Motorsports in nine out of thirteen rounds. The Swede had a very good start of the season. At Homestead-Miami Speedway the 20-year-old driver finished second behind David Empringham. Fredrikson scored another podium finish at Nazareth Speedway where he finished third. After a number of retirements Johansson Motorsports replaced Larsson with Jeff Ward. Larsson tested for Alan Docking Racing at Pembrey Circuit looking to compete in the British Formula Three Championship. However this deal never came to fruition.
Return to racing
After not racing between 1999 and 2009 Larsson returned to competitive auto racing in 2009 in the Porsche Carrera Cup Scandinavia. Larsson finished third in the championship behind Joakim Mangs and Tony Rickardsson. The fast Swede won six out of sixteen races. The following year he won nine races and finished second in the championship. For 2011 Larsson competed in a variety of racing classes. He competed a BMW Z4 GT3 entered by WestCoast Racing in the Swedish GT, ADAC GT Masters and the 24 Hours of Nürburgring. Larsson won three out of three races in the Swedish GT. For 2012 Larsson joined the newly formed TTA – Racing Elite League after the series split from the Swedish Touring Car Championship. At Anderstorp Raceway Larsson started from pole position, won the race and also set the fasted race lap. The driver from Falkenberg was the bestBMW M3 driver finishing fourth in the standings behind two Volvo S60's and one Saab 9-3. After the formation of the Scandinavian Touring Car Championship Larsson remained at WestCoast Racing. For 2013 Larsson did not win a race but he scored two-second-place finishes and two third-place finishes. Larsson finished sixth in the standings.