Select the Code Entry option at the Extras menu, then enter one of the following codes to activate the corresponding cheat function:
Infinite health
Enter 94677 as a code.
Infinite stealth
Enter 53467 as a code.
Infinite copper
Enter 23637 as a code.
Infinite Chi
Enter 24463 as a code.
Double damage
Enter 34743 as a code.
One-hit dishonor
Enter 54641 as a code.
All treasure maps
Enter 37437 as a code.
Character concept gallery
Enter 97831 as a code.
Defeating the fire machine
This is the machine you must fight in order to find Katara. Dodge the fire bending. Try running left to right, then right to left. Continue this until you see a flashing light near it, then attack it. Hit it with Aang. You may use a Chi attack but just a plain attack should work just as well, however it takes time. You will have Saka (Katara's brother) fighting with you to do double damage. Once it has around a quarter of its HP gone, the machine will start throwing fire around. Keep a safe distance from this attack. It causes no real threat to your or your partner as long as you stay as far away as possible.
Defeating the Maker's last machine
You can wait for it to stop attacking, or you can attack it, which will barely affect it. Once it is done attacking, you must attack the sides which turn red.
Defeating the prison guard
At first he will shoot fire balls at you. Keep moving left and right, and closer to him. Once you get close enough he will stop and try to hit you with his stick. Take a few steps back and let him try to hit you. Move, and when he stops, hit him. Do this repeatedly until he eventually kneels down. Then, hit him as many times as possible. He will not fight back. When he gets up, repeat the same process until there is a short intermission sequence. He will then use attacks such as curling up in a ball and swinging his bat in a figure eight style on both sides. Wait until he is done and then hit him. Repeat this until he is defeated.
Easy experience
Whenever you are in battle you can go back later to get more experience.
Getting easy cash and exprerience
The best thing to do is to find items, kill lots of enemies and collect the money. The items you have collected you can sell at a merchant and you can get some very hefty prices for stuff. Also for experience it is a good idea to complete the quests and kill every enemy you see as this helps to get exp. Also use all the characters as different moves get different exp.