Steal Opponents Emblem
This code is used to steal an enemies emblem in the Arena. To do this, you must first defeat the opponent. Once beaten, you can go back to the opponent selection screen in Arena mode. Highlight and select someone you have beaten and then press SELECT + START. You should hear a sound indicating that the code has worked. Now, if you want you can go to the Garage and select Edit Emblem and alter it or wear it as it is.

Create overweight A.C.'s
After beating the mission mode in Armored Core 2, you are allowed to create overweight A.C.'s. In the garage, a warning will flash telling you that your A.C. is overweight, but you will still be able to use it. You must get to the end credits to activate this cheat.

Hidden Parts
On the mission to stop the surface weapon, immediately jump over the two enemy surface weapons. Look around near the rocks to find the Karasawa mk. II sitting on the ground. In the A.C. test room, if you shoot the circle in the ceiling, it will blow up, revealing a secret area. You will need a light A.C. or good boosters to go up the shaft into the area. Here you will find a new Radar part.

First Person View
Hold Triangle + Square + Start. Release all buttons, then press Start again.

Easy Victories
In the arena play on the abandoned highway and fight behind the building you start at and stay really close to the out of bounds marker and more often than not your opponent will leave mission area and you win.

Infinite Energy
This cheat if for infinite generator energy, not AP. At any time during gameplay, press L1+L2+L3+R1+R2+R3. The screen will flash a "System error" and a "limiter release" message on the left. This is great for extended over boosts or weapons that drain a lot of energy. It lasts for a limited time.