In skillet, heat oil and cook sausages until browned. Drain well, slice into thirds and set aside.
Drain pineapple, reserving juice.
In saucepan combine sugar and cornstarch, stir in juice and heat until thickened. Stir in sausages, pineapple, vinegar and soya sauce. Cook 5 minutes to heat through, stirring to coat meat and pineapple.