GTA IV isn't the hardest game around, but hey, maybe you're not the best gamer around. Maybe you've got stubby thumbs. Maybe you can game, just can't be bothered, and want the ability to spawn sports cars in front of you just for kicks. If so, take note of the following GTA IV cheats, which will do things like restore Niko's health, give you all the game's weapons, change the weather and adjust your wanted level. ACHTUNG: these mess with your saved game files and can stop you earning achievements, so you might want to turn autosave to the "off" position if you want to safeguard your progress against a tragic corruption.
Just enter the following numbers into Niko's phone (they should work on both 360 and PS3):
Restore Health
4825550100
Restore Armour
3625550100
Equip Baseball Bat, Handgun, Shotgun, MP-10, M4, Sniper Rifle, RPG, Grenades.
4865550100
Equip Knife, Molotovs, Handgun, Shotgun, Uzi, AK47, Sniper Rifle, RPG
4865550150
Remove Wanted Level
2675550100
Raise Wanted Level
2675550150
Change Weather/Lighting
4685550100
Spawn Annihilator
3595550100
Spawn Jetmax
9385550100
Spawn NRG-900
6255550100
Spawn Sanchez
6255550150
Spawn FBI Buffalo
2275550100
Spawn Comet
2275550175
Spawn Turismo
2275550147
Spawn Cognoscenti
2275550142
Spawn SuperGT
2275550168
Grand Theft Auto IV - Cheats [GTAIV.net]