Our ECU's cannot be changed, they're not carckable.
Nothing is uncrackable, that's impossible.
16 bit key, that's a F***ing cakewalk, dude. Try cracking 128 bit crypto keys, it can be done.
Most tuners work with open source code or make their own anyways, but cracking the code wouldn't be hard; I know a few guys that could do it in their sleep.
If I had a ROM dump from the ECU, I'd crack it myself... ^_^ Anyone got a Rom Dump from the ECU?
Also, couldn't you just use the J-spec ECU with the 2ZZGE? that ECU is hotter than ours. Dump it's ROM and put it on a FlashROM, that is, if the factory unit doesn't already have it (most ECU use flashrom these days) then just burn the rom to your ECU and your all straight.