ECU for Celica ZZT-230 Question

Is it possible to swap a Celica ECU that is OBD2 compliant, with one that is not compliant? (IOW Pull the old one out and plug the new one in)
The reason I ask is that in New Zealand, where I live, all Celicas are
compliant with OBD2.
OBD2 compliance for cars, was not made compulsory until 2006, unlike in the US where this came into being in 1996.
If straight swapping is possible I would like to import an ECU from the US. ->> Any offers??
The car is a Y2K model imported from Japan in 2004, ZZT-230 Engine 1ZZ-FE.
To date I have tried a number of scanners and not one of them can connect to the ECU, to for engine fault codes.
Hope some one can help here.