hi, so i finally gotten my i4 unlocked and before that i was using the 3g, not 3gs. The 3g is running on 3.0 and is unlocked and jailbroken, what i want to do now is sell it so i want to erase everything on it, but i want to sell it as unlocked. So whats the best thing to do?
^Best thing is to load a stock 3.1.3 firmware. It stays unlockable with ultrasn0w and contains the best & fastest iOS for the 3G. If you also want it jailbroken, use redsn0w 0.9.4.
You would be able to accomplish the above by simply downloading a stock 3.1.3 from the downloads section here under Firmwares.
You will also need 3.1.2 for the jb and unlock process. So get that too.
Just open iTunes and hold shift and click restore, browse to the 3.1.3 ipsw and let iTunes restore.
Then when you get error 1015 use TinyUmbrella to exit recovery mode.
Then if you have an official SIM, activate it in iTunes. If you don't have a SIM, just run redsn0w 0.9.4 on it. In redsn0w browse to the 3.1.2 ipsw here and follow the instructions on-screen.
Then go to Cydia and install ultrasn0w and you're good to go.