Does the PS2 run off a PROM or EPROM ??
If so, then there might be some way to reflash it. I don't have a PS2 so I'm guessing here and probably not helping the thread at all. Sorry.
Because mod-chipping a car is not illegal. It will void your warranty, but it is legal. Chipping a PS2 with the intent to play burned (ie illegal copies) of software and DVD titles is not.
Thats a good legal question. Is it illegal to render your PS2 capable of playing illegal (copied) discs ?? What law are you breaking ??
Anyway, good luck if you can do it. !!