Mega Man Battle Network 4 Gameboy Advance Cheats

Hard mode
Finish the game under normal difficulty. Then, pick the CONTINUE choice to access a new hard mode.

Super Hard mode
Finish the game under hard difficulty. Then, pick the CONTINUE choice to access a new super hard mode.

Woodman's Wood Poles
When you need to find woodman on the net for Sal, don't worry about the wood poles, as long as you have undershot installed, you won't die. Note: Viruses can still kill you though.

Castillo Entrance
When you're supposed to give the darkchip to the blacknavi in Park 2, but you don't know how to open the Castillo door, look at the note by the unconscious navi, you see the numbers under the letters, they are the letter's corresponding numbers, so put the letters in order from greatest to least, the new orders of letters is the code.

Soul Unison
Through the game, the Souls of those you battle with in tournaments will resonate with Megaman- Soul Unison.

Red Souls:
1.Roll Soul
2.Guts Soul
3.Thunder Soul
4.Fire Soul
5.Wind Soul
6.Search Soul
*******************
Blue Souls:
1.Blue Soul
2.Number Soul
3.Metal Soul
4.Junk Soul
5.Aqua Soul
6.Wood Soul

Bass
Yup, Bass is still in this version. The black navi, the rougue who has been beat by megaman time and time again keeps coming back with more evil, and more powerful each time. However, you can't reach him without an "S ID." This means that once you have completecd the Standard Chips portion of your data library the door will open.

Fortunatley, bass doesn't have a protective aura in this version. Although, his attacks make up for that, His HP is 2000 and his Darkness Overload causes 300 damage (600 against BassSP). Be sure to pack a Barr200, it will help you a lot against some of his attacks.

P.S.
Bass is in Undernet 6, but to get to him, you must go through Undernet 5, past the door that won't open without the unison of 6 souls. After you beat Bass, he will flee to the Black Earth.

Dark Chips
In the game, the only dark Chips that will appear in your fold are below, and next to them is the effect that they give you:

DarkCanon: Causes a buster bug that reduces stats to 1
DrkSword: Causes a movement bug that forces megaman to move forward
DarkBomb: Causes a movement bug that forces megaman to move backwards
DarkVulcn: Causes a movement bug that reverses megamans directonal controls
DrkLance:Causes a bug that removes five random chips from you folder from play
DrkSpred: Causes a bug that turns any panel megaman steps off of into poison panels
DrkStage: Causes a bug that gives you one less chip space on the custom menu
DrkRecov: Causes a bug that rapidly drains megaman's hp, even when choosing new chips

If the dark chips are used a lot, then megaman will automatically enter a battle in Evil form and be able to use the Dark Chips at any time.