From what i can tell this was just released today
Invincibility cheat code for Xbox 360
RIGHT, A, RIGHT, LEFT, RIGHT, RB, RIGHT, LEFT, A, Y
Basically Does exactly what the cheats says however it only last for 5 minutes. When you put the code in it shows you a timer...at which once it ends you may input the same cheat code again for another 5 minutes of pure glorious rampage through Los Santos.
Shout out to @complexMag for the article Follow me @G3tAtMeBro