The 2000 have drive by wire electronic throttles. They also

have variable valve timing and some models are available with

a 5 speed automatic transmission (vs. a 4 speed in 97). I forget

if the variable valve timing is on exhaust or intake or both (there

were various combinations by year and if you had a turbo engine

vs. normally aspirated). I think all engines also have oil cooling

for the pistons by MY 2000 (which was previously only found on turbo models -- there were some issues with the valve mechanisim being very noisy though).

So, yep, the engine did continue to evolve and in some fairly

major ways.