There are several cheats for Grand Theft Auto: San Andreas. These cheats are for the PC version of the game; and, they do not work for any other version.
According to IGN Entertainment, it is possible to input cheats for Grand Theft Auto: San Andreas by typing in certain words or phrases. For example, typing SPEEDFREAK means all cars have nitro. Below is a list of some cheats for Grand Theft Auto: San Andreas on the PC, provided by IGN cheats. Simply type these words into the game at any time with no spaces:
Most codes can be undone by retyping the same phrase while the code is activated. Some are permanent, though, so each player should save before using them.