Tony Hawk's Pro Skater 4 Cheats...
Alternate outfit
Spend $40 at the skate shop.
Always special
Spend $240 at the skate shop.
Hidden skater
Complete the Pro Challenges to unlock Mindy, Frycook, Momo and Roger.
Jet pack mode
Spend $40 at the skate shop. Press B to fly up, A to move right, L to move left, and R to hover.
Matrix mode
Spend $40 at the skate shop.
Moon physics
Spend $40 at the skate shop.
Perfect manual balance
Spend $240 at the skate shop.
Perfect rail balance
Spend $240 at the skate shop.
Pro Challenge
Get all goals in a level. This must be done before any of the buyable cheats can be used for that skater.
Pro Skater animations
Win the Pro Objective for that skater.
Skitchin'
To skitch a car, go behind a car and hold A + B.
Stud mode
Spend $240 at the skate shop.
The Zone level
Get all 90 packages to unlock The Zone.
Tony Hawk's Pro Skater 4 board
Go to the skate shop and select "Change Deck". The board under "Custom" is the Tony Hawk's Pro Skater 4 board for Neversoft skaters.
Turbo mode
Get all the gaps on each level except The Zone to unlock the Turbo option.
Walking
Hold Down until you stop moving. Then, hold A to pick up your board and start walking.