No changes dont expect the car to become a rocket, Just expect it to be stable and smooth, You dont feel that the engine has to struggle or that the RPMs are rising (engine noise should be minimal)
Just for the sake of it if your car has crossed the 50,000 km range change the Automatic transmission Fluid as well, knows as ATF (toyota TIV goes in it,)
a fuel average of 10-14 kms is an ideal average for 99-04 Vitzes, Depends on how you drive, Where do you drive, Petrol quality and roads etc.
Check brakes, Leakages of any kind, in the car and your good to goo, The 99-04 Vitzes are Lacker hazam pathar hamaz kinda strong cars, Its a mini Corolla in all ways.