The Perfect Manual
For an easier time with railings and various other skating tricks that require careful balancing, simply enter the appropriate cheat code in the menu screen. Enter the "Options" tab and under the "Cheats section," type in the code "straightedge". Just go through the on-screen QWERTY board to key in the letters in the absence of a keypad. For some other game versions, the code may not work. If the version of the game is not accepting the code try keying in "keepitsteady" instead.
Perfect Manual Not For Career Campaign
One feature of "Tony Hawk's Underground 2" which gives it a high rating in the area of "game life span" is its numerous gaming modes available. When playing majority of the game modes, you should not have a problem with the Perfect Manual code. However, note that these codes for activating Perfect Manual will not work when playing under the Career Campaign mode of the game. This is because the game developers want players to advance the story mode using natural skills. Also, the scoring system among players will be fair.
Unlock All Levels
It is advisable that you attempt to clear the game first without the use of cheat codes. This is especially important if you want to clear the career campaign mode, wherein many cheat codes will not work. When needed, use the code "accesspass" to unlock all levels.
Other Cheats
When entering these cheat codes, the procedure is the same. Just go to "Menu," "Options" and "Cheats." Some other cheats are: "likepaulie" to activate special all the time; "frontrowseat" to enable all movie clips; "bedizzy" and "oldskool" for Natas Kaupas; "4wheeler" to have Paulie on skateboard; "sellout" to enable the Nigel Beaverhousen; and "notvito" to unlock Phil Margera.