Core i CPU ME region

When you download an EFI from the Repository site is like swapping the EFI chip with another computer that doesnt have the EFI password. You can't change the password by replacing the EFI chip without messing up the ME region - the intel management engine. This is true for all core i intel platforms. The ME region is the part of the BIOS that speaks to the PCH and controls things like clock speed, and performance of the integrated GPU. If you mess with this it will run incredibly slow all the time, and be completely useless. You have to reprogram the BIOS with a clean ME region. When the machine first turns on, the BIOS communicates with the PCH and creates a handshake, similar to the first time you log into a new machine using ssh. If the PCH realizes the BIOS has a different handshake for the ME region, they will not communicate, and the machine will run like $@$* This is applicable to anything core i.

Soooo how to you clean the ME region???!

My research shows all ME region starts with "20 20 80 0F"

As you said that "The ME region is the part of the BIOS that speaks to the PCH and controls things like clock speed, and performance of the integrated GPU."
Mac's password it is an Apple child, it stored into special volume on the flash and doesn't have direct relation to the ME. So, it works like an authorization with password file. If you change the file with password then password will changed too.