In 1982, Josjö was Swedish champion at both 200 and 400 metres. At the 1982 European Championships in Athens he represented Sweden in both the individual 400 metres and the 4 × 400 metres relay; in the individual event he was eliminated in the heats, while the Swedish relay team qualified for the final and placed eighth. Josjö also competed in both events at the inaugural 1983 World Championships in Helsinki; his best race there was in the relay heats, where he split an estimated 45.79 on the second leg as Sweden qualified for the final. In the individual 400 metres Josjö faded in the final straight in both of his races and went out in the quarterfinals.