just bought a s200 ecu of a guy on the internet

[alan]

wanted to know what ineed to down load the softwere and want to know what else i need so i can tune my own car

[Spunkster]

If you want to be able to tune yourself, you will be much better off just upgrading to the s300 as it is easier to work with and has more options and features. It will also be cheaper than purchasing the Romeditor software, a programmer and emulator.