Grand Theft Auto IV Hints

While playing the game, press Up to display Niko's cell phone. Press Up again to access the keypad. Then, enter one of the following codes to activate the corresponding cheat function. Once a code has been entered correctly, a new "Cheats" menu option will be available on your phone, below "Options", where you can access the cheats without having to enter the phone number again. Note: Do not save the game after enabling a code to avoid unforeseen problems. Enabling some cheats will prevent the indicated achievement(s) from being earned. You can usually only spawn one vehicle at a time. Any previously spawned vehicles will disappear. However, if you spawn a vehicle, save the game, and load again, you can spawn another one and your original will not disappear. You must have it in your parking space in front of a safehouse or it will be gone before you have a chance to spawn another.

Full health and armor

Dial "3625550100" on the cell phone. If you enter this code while in a vehicle, it will also repair it. Note: This phone number translates to "DOC-555-0100". This code prevents the "Cleaned The Mean Streets", "Finish Him", "One Man Army", and "Walk Free" achievements from being earned.
Full health, armor, and ammunition

Dial "4825550100" on the cell phone. If you enter this code while in a vehicle, it will also repair it. Note: This phone number translates to "GTA-555-0100". This code prevents the "Cleaned The Mean Streets" achievement from being earned.
Weapons tier 1

Dial "4865550100" on the cell phone. This will unlock the baseball bat, handgun, shotgun, MP5, M4, sniper rifle, RPG, and grenades. Note: This phone number translates to "GUN-555-0150". This code prevents the "Cleaned The Mean Streets" achievement from being earned.
Weapons tier 2

Dial "4865550150" on the cell phone. This will unlock the knife, Molotov cocktails, handgun, shotgun, Uzi, AK47, sniper rifle, and RPG. Note: This phone number translates to "GUN-555-0100". This code prevents the "Cleaned The Mean Streets" achievement from being earned.
Remove Niko's wanted level

Dial "2675550100" on the cell phone. Note: This phone number translates to "COP-555-0100". This code prevents the "One Man Army" and "Walk Free" achievements from being earned.
Add one star to Niko's wanted level

Dial "2675550150" on the cell phone. Note: This phone number translates to "COP-555-0150".
Spawn Annihilator police helicopter

Dial "3595550100" on the cell phone. The Annihilator is armed with rockets. Note: This phone number translates to "FLY-555-0100". This code prevents the "One Man Army" and "Walk Free" achievements from being earned.
Spawn Cognoscenti

Dial "2275550142" on the cell phone. Note: This phone number translates to "CAR-555-0142".
Spawn Comet

Dial "2275550175" on the cell phone. Note: This phone number translates to "CAR-555-0175".
Spawn FBI Buffalo

Dial "2275550100" on the cell phone. Note: This phone number translates to "CAR-555-0100".
Spawn Jetmax

Dial "9385550100" on the cell phone. Note: This phone number translates to "WET-555-0100".
Spawn NRG-900

Dial "6255550100" on the cell phone. Note: This phone number translates to "MBK-555-0100".
Spawn Sanchez

Dial "6255550150" on the cell phone. Note: This phone number translates to "MBK-555-0150".
Spawn SuperGT

Dial "2275550168" on the cell phone. Note: This phone number translates to "CAR-555-0168".
Spawn Turismo

Dial "2275550147" on the cell phone. Note: This phone number translates to "CAR-555-0147".
Change weather and brightness

Dial "4685550100" on the cell phone. Note: This phone number translates to "HOT-555-0100".

Easy money
Go to an ATM, then cause a traffic jam to the area. Wait for someone to take money from the ATM, then kill him or her. Make sure to block any nearby roads so the ambulance cannot get to the murdered victim. Take the money they dropped on the ground. Then, run a short distance away, and go back. The money should have respawned on the ground. You can repeat this as many times as desired. You can also kill more people taking their money from the ATM to increase the amount of money that respawns.

Repairing the engine
If the vehicle you are driving breaks down and the engine will not start, call any number from your phone book, and your engine should start again.

Get a Statue of Liberty T-shirt
Go to the statue of liberty and walk up to the second level. Walk through the door (it doesn't swing open, just go through it) and the game will load for a second and you will walk out with a new t-shirt with the statue of liberty on it.

Mr. tasty + GTA Theme Cheat
When inside a Mr. Tasty Ice Cream truck, one of the the songs the truck plays is called the GTA Theme, in a cycle order it is usually played after Flight of the Bumblebee. While playing the song, call ZiT, and a text message will confirm telling you the name of the song. As soon as the message is answered, a Cheat Activated confirmation will appear, and the cheat will appear in the Cheat section in your phone.

Effects: Cheat gives you full healith and Body Armor

First, you'll have to have access to Happiness Island. Once you're able to go there legally, find the Helicopter Tours (which is directly east of Happiness Island) and steal a helicopter. Fly to Happiness Island and over the Statue of Liberty, then jump out of the helicopter at the statue's feet. You should land on the topmost tier of the statue, which is basically a square platform with a door in the center of each side. Run around the platform until you see a door with a plaque on either side of it that reads, "No Hidden Content Here." It may seem like you cannot go through the door, but you can-- it doesn't open, you simply walk THROUGH the door. Inside, you'll find an empty room with a tall ladder. Climb it, and when you reach the top, look up; there is a gigantic beating heart, held in place by chains.

If your trying to steal a car for Brucie or Stevie but theres a copper around and you dont want to risk a wanted level go up to any car with a person inside and run up to the door and press B to push it. this counts as damage to the car and the person in the car should get out and try to beat you up. run and stand a short distance away from the cop so that the driver has enough time to run let the driver hit you and the cop will come to arrest him. the driver should run away, thus leading the cop away to leave you alone with the car. you can also use this method to assasinate people or any other reason you have.

Reach the indicated level of friendship with the corresponding character to unlock their special friendship ability:

Alex (screen name "LiberatedWoman")

Method: Look for the personal ad from "LiberatedWoman" in the "Women seeking men" section of the "www.c.raplist.net" (i put a dot infront of c.rap but go to c,raplist i'm just doing this so it doesn't get blocked.) Alex is somewhat of a self-centered, spoiled rotten rich girl. She will compliment Niko for wearing expensive clothing and driving expensive cars. She will also write about her exploits with Niko in her blog at "www.blogsnobs.org". Reach 80% friendship with her.

Special ability: 50% off at all clothing stores.

Brucie

Method: Take him bowling, drinking, eating, strip clubs, shows, helicopter tours, and boating to reach 70% friendship.

Special ability (Chopper Ride): Call Brucie, and he will fly his helicopter to you. This allows you to fast travel to various portions of the city.

Carmen (screen name "SoboHoe")

Special ability (Health Boost): Restores Niko's health over the phone. She will call Niko every chance she gets.

Dwayne

Method: Take him to strip clubs, eating, drinking, shows, and bowling to reach 60% friendship.

Special ability (Extra Help): Call Dwayne to have a car full of gang members follow you.

Kiki (screen name "LawChick")

Method: Date LawChick via "www.love-meet.net" through the in-game internet. Take her out a few times to reach 75% friendship. When dropping her off, select the "Try your luck" option. Afterwards, she will call you and say she can clear the feds.

Special ability (Remove Up to 3 Wanted Stars): Call her on your cell phone, and select "Clear wanted levels".

Little Jacob

Method: Take him to darts, shows, pool, drinking, eating, and strip clubs to reach 60% friendship.

Special ability (Discount Guns): Call Little Jacob, and he will drive out a car full of guns for you to buy.

Packie

Method: Take him to strip clubs, shows, darts, drinking, bowling, pool to reach 75% friendship.

Special ability (Boom?): Call Packie, and he will make a car bomb for you.

Roman

Method: Take him to bowling, darts, drinking, eating, pool, shows, and the strip club to reach 60% friendship.

Special ability (Free Ride): Call Roman, and he will send a free cab.

Stevie

Method: Successfully complete all 30 of his vehicle thefts.

Special ability: The South Bohan garage will now offer money for any vehicle you deliver. The better the condition, the more money you will earn.

To enter a cheat code, bring up your phone by pressing Up, then Up again to access the keypad. (You must first do a couple of quests for Roman to get a phone this works on). Once a code has been entered correctly a new Cheats menu selection is available on your phone, below Options, where you can access the cheats without having to enter the phone number every time. NOTE! Some achievements will be blocked when using the cheats.

Get Full Health and Weapons:

Get Weapons:

Get Advanced Weapons:

Get Full Health:

Wanted Level Down:

Wanted Level Up:

Change Weather:

Spawn Cognoscenti:

Spawn FBI Buffalo:

Spawn Turismo:

Spawn Comet:

Spawn SuperGT:

Spawn NRG900:

Spawn Sanchez:

Spawn Police Chopper:

Spawn Jetmax:

100%:

In-Game Maps:

Call 911:

Get Claude's outfit:

Hidden Shirt:

The heart of the Statue:

Purple Dildo:

GTA Graffitti:

GTA portraits:

Old GTA character's names graffitti:

OG Loc CD:

Golf Course Land Marks:

Easy One Man Army achievement:

Car repair glitch:

Easy Gobble Gobble Achievement:

Easy Walk Free Achievement:

Easy One Man Army Achievement:

100%:
To get 100% you have to complete the following:

* Complete all Main Missions.
* Complete all 10 Drug Deliveries.
* Complete all 10 Races.
* Complete all 10 Assassination missions.
* Complete all 30 car thefts.
* Collect all 10 cars for the Exotic Exports mission.
* Unlock all five friend's special abilities and complete the activities with Little Jacob, Brucie and Packie.
* Beat the computer or an online friend in all activities.
* Find all Random Characters and complete their missions (except for Jeff, Cherise, Clarence & Ivan).
* Complete all 30 Most Wanted Missions.
* Complete all 20 Vigilante Missions.
* Kill all 200 Pigeons.
* Complete all 50 Unique Jumps.

In-Game Maps:
If you go to an Internet café and enters the URL www.whattheydonotwantyoutoknow.com you will get to a page with maps of all weapon pickups, health, armor, vehicle locations, unique jumps and pigeon locations.

Call 911:
If you call 911 on your phone you can select if you need an ambulance, police car or a fire truck. Make your selection and wait for them to arrive so you can steal the vehicle. If you get into the ambulance you will get a small health boost and if you get into the police car you will get 5 shotgun shells.

Get Claude's outfit:
If you choose the kill Playboy X you will take over his safehouse. If you change clothes in that safehouse you can choose to wear the outfit Claude (the main character in GTA III) was wearing. Black jacket, green pants and black/white shoes.

Hidden Shirt:
Get to Happiness Island. Run up to the base of the statue to find a shirt on the ground. Walk over it to put it on. It has a picture of the statue and the text Happiness is... on the front and the text ...land on the back.

The heart of the Statue:
Get a helicopter and fly to Happiness Island. Jump out of the helicopter at the top of the statue's base so you'll land by it's feet. You can not take the stairs this high. Look at the sign next to the door. It says No Hidden Content Here. Enter the door and climb the ladder inside the statue. You will find a big, red, beating heart held in place by chains.

Purple Dildo:
Head inside the old, abandoned Casino where the last mission takes place, at the north end of Alderney. Look at one of the trash piles on the ground to find a purple dildo sticking out.

GTA Graffitti:
Across the road from Bank of Liberty you can find a house covered in graffitti. Some of the artwork is from old GTA titles.

GTA portraits:
Across the street from the museum in Algonquin you can find a portrait painter. The portraits are of old GTA characters.

Old GTA character's names graffitti:
Go inside one of the pink houses near Manny's community center. Go to the back of the inside and look at the wall. You will find graffitti with names from a lot of old GTA characters, like Claude, Tommy, Toni, etc.

OG Loc CD:
In your Bohan safehouse you can find a CD by OG Loc from San Andreas on the floor.

Golf Course Land Marks:
At the mini-golf course at Firefly Island you can find a small version of the giant chicken from San Andreas, the lighthouse from the GTA III version of Liberty City, the Watts Towers from Los Santos and the Ocean View Hotel from GTA: Vice City.

First escort yourself to the helicopter tours. Getting a taxi will save time. Once you arrive there go to where the helicopters are and you will see that there are NO security guards. Now all you have to do is counter the the people by pushing them then tappping A to dodge as soon as the person throws a punch. Stick to the men as the women punches are alot quicker. After they throw the punch repeatedly press the B button and you will see that he does a combo. Replacing B as X does a different combo i.e kicks. Another thing is that if you run low on health as you exit the Helicopter Tours there is a hotdog stall. It is better to get one before you enter. Good Luck!! :D

If you have unlocked the internet cafe named "Tw@t" One is in Broker near "Perestroika" the Russian cabaret you may have encountered. Go on to the computer and log on. Then in the adress type:
www.whattheydonotwantyoutoknow.com
It is very long but it is worth it, it tells you the location of everything with a pinpoint map with small red dots to tell you where it is.

The fastest car on the game is hidden behind the old mansion at the top right corner of alderney. I pretty sure its at the back of the house. Good luck!! If you would like me to post anymore cheats or anything else just ask.

The sultan RS is a rally car that is hidden on the third island. well at the very top of the third island there is like a massive metal garage(where you start when you play with your friends online). well up the road from there there is a dirt track that leads to a broken house. there are some garages wat are smashed up behind there is where the sultan RS is.