Here are some hints and cheats for Grand Theft Auto IV: The Ballad of Gay Tony (PC version)…
Unlockable: No Ammo Cap in The Ballad of Gay Tony
Beat the game with 100% completion to unlock an infinite ammo cap.
Unlockable: NOOSE APC in The Ballad of Gay Tony
Kill 50 seagulls to unlock the Noose APC at the construction site.
Hint: Easy Health and Armor Boost in The Ballad of Gay Tony
Once you have unlocked base jump challenges in TBoGT you can start a base jump challenge to refill your health! Go back and do it again and you’ll have full armor.
Unlockable: The Ballad of Gay Tony Safehouse Items
Peform the actions below to unlock the following safehouse items:

* Parachute – Complete all 20 base jumps
* .44 – Complete 10 gang wars
* Advanced MG – Complete 20 gang wars
* Explosive Shotgun – Complete 30 gang wars
* Gold SMG – Complete 50 gang wars
* Sticky Bombs – Complete 40 gang wars

Cheat: The Ballad of Gay Tony Weapon Pack
Call 486-555-0100 for the following weapons:

* Knife
* Advanced Pistol
* Explosion-Pellet Shotgun
* Silenced P90
* LMG
* Advanced Sniper
* Grenade Launcher
* Sticky Bombs

Cheat: Vintage Cheat List
These cheats from GTA IV’s main story are also effective in the downloadable content. Take out your phone by tapping Up on the D-pad twice, then enter the number below for the desired effect:

* 267-555-0150 – Raise wanted level
* 267-555-0100 – Lower wanted level
* 362-555-0100 – Replenish armor
* 482-555-0100 – Replenish health, armor, and ammo
* 468-555-0100 – Alter weather
* 486-555-0100 – Weapon pack 1
* 486-555-0150 – Weapon pack 2
* 948-555-0100 – Song information
* 359-555-0100 – Spawn an Annihiliator
* 227-555-0142 – Spawn a Cognoscenti
* 227-555-0175 – Spawn a Comet
* 227-555-0100 – Spawn an FIB Buffalo
* 938-555-0100 – Spawn a Jetmax
* 625-555-0100 – Spawn an NRG-900
* 625-555-0150 – Spawn a Sanchez
* 227-555-0168 – Spawn a SuperGT
* 227-555-0147 – Spawn a Turismo

O game Grand Theft Auto IV é um verdadeiro fenômeno de vendas no mundo. Na primeira semana o tão esperado jogo vendeu 6 milhões de cópias e arrecadou US$ 500 milhões em vendas.
Quem já comprou o GTA IV para PS3 ou XBOX 360, pode testar os códigos abaixo, digitando no celular do personagem: 

        Health (vida)

• 482-555-0100

• Armor (armadura)
  362-555-0100

• Weapons #1 (armas 1)
  (Bastão de beisebol, Handgun, Shotgun, MP5, M4, Rifle Sniper , RPG, Granadas)
  486-555-0100

• Weapons #2 (armas 2)
  (Cuchillo, Molotovs, Handgun, Shotgun, Uzi, AK47, Rifle Sniper, RPG)
  486-555-0150

• Remove Nível de Procurado
  267-555-0100

• Aumenta Nível de Procurado
  267-555-0150

• Mudança de clima/Brilho
  468-555-0100

• Spawn Annihilator (aniquilador)
  359-555-0100

• Spawn Jetmax
  938-555-0100

• Spawn NRG-900
  625-555-0100

• Spawn Sanchez
  625-555-0150

• Spawn FIB Buffalo
  
    227-555-0100

• Spawn Comet
  227-555-0175

• Spawn Turismo
  227-555-0147

• Spawn Cognoscenti
  227-555-0142
• Spawn SuperGT
  227-555-0168