Is the subaru 2002 impreza difficult to maintain?

No the subarus run a long time especially if you change the oil and filter every 3,000 miles and say every 25,000 to 30,000 change the spark plugs and wires and every 30,000-40,000 change the fuel filter.Basically just do routine maintaining of the vehicle and its not uncommon for them to run 200,000 miles or more.