I have a 1990 Prelude Si ALB with a JDM B20A engine in it. (Engine is
not the original, of course) My ECU is a PK3, which is the original ECU
from the factory, and the car runs fine. I've noticed that most 89-91
Prelude Si's have a PK2. Does anyone know the difference between the
two types?

Thanks!

Jon