1. Use Niko’s mobile
You can dial the following numbers on Niko's phone during the game to get instant results. Beware: using them can affect your missions and achievements.
468-555-0100 Change weather 486-555-0150 Get a different selection of weapons 486-555-0100 Get a selection of weapons 267-555-0150 Raise wanted level 267-555-0100 Remove wanted level 362-555-0100 Restore armour 482-555-0100 Restore health 948-555-0100 Song information 227-555-0142 Spawn a Cognoscenti 227-555-0175 Spawn a Comet 938-555-0100 Spawn a Jetmax 625-555-0150 Spawn a Sanchez 227-555-0168 Spawn a SuperGT 227-555-0147 Spawn a Turismo 359-555-0100 Spawn an Annihiliator 227-555-0100 Spawn an FIB Buffalo 625-555-0100 Spawn an NRG-900
2. Locate pick ups
Enter this password into PCs within the game to find weapon, health, armor, vehicle, pigeon, ramp, and entertainment locations around the city:
www.whattheydonotwantyoutoknow.com
3. Get easy money
Cause a traffic jam to block the roads around an ATM and you can kill people withdrawing money and stop ambulances arriving. Take the cash and run away, then return to the murder scene and you’ll find the money has respawned. You can keep no doing it and kill more ATM customers to increase the number of notes you can pick up at each visit.
4. Find the Heart of Liberty City
It’s the ultimate GTA IV Easter Egg. Once you can visit Happiness Island legally steal a chopper from the Helicopter Tours and fly it over the Statue of Liberty. Jump out at the statue's feet and you’ll land on the top tier. Find a door with a sign that "No Hidden Content Here" and run straight through it rather than trying to open it. Climb the ladder and look up to find a beating heart in chains.
5. Unlockables