Can you use ipod touch 2g firmware for a 3g iPod touch?

Sadly, no i tried to use 3g or 1g firmware on my iPod touch 2g and it didn't work.

You have to have the exact firmware file. Like if you have an ipod touch 1g with 2.2.1 firmware you have to have the file made for a 1g itouch that has 2.2.1 firmware