The online service of Gran Turismo 5 will undergo maintenance during the following hours:
Start: 04/22/2013 23:00 EDT
Finish: 04/23/2013 01:00 EDT
Start: 04/25/2013 04:00 EDT
Finish: 04/25/2013 06:00 EDT
During the maintenance, you will not be able to connect to any of the online services.
*Please note that the exact time of the maintenance may slightly vary.
"Changed game code to disallow people from illicitly altering game data to improve the performance of cars beyond what they are intended to be capable of"
We can hope...