Will ECU remember fault codes with no power?

[nuvolari]

Regarding a 2000 986S (Motronic 7.2) that has been apart for +3 years, I'm curious if the ECU will still have the fault codes and other stored info that a Durametric will be able to read? This is with no power for this amount of time and with the ECU disconnected.

Especially want to know overrevs and cam deviation but I think cam deviation is only readable in real time or does the ECU save anything pertaining to this?

Any other info that would be worth looking for? Of course, all of this is only valid if the ECU remembers information this long without a power source?

Thanks.