Bullet Bill 2 Is a Toy, Not a Video Game

Bullet Bill 2 is a physical remote-controlled toy (released ~2008 by Nikko), not a video game. Therefore, it has no cheat codes.

What It Is

• Battery-powered RC car shaped like Bullet Bill (Mario enemy).
• Infrared controller, simple forward/turn controls.
• Marketed as "RC Bullet Bill 2" — successor to smaller v1.

If You Meant a Video Game

• Mario Kart series: Bullet Bill is an item (transforms player into auto-pilot missile).
• New Super Mario Bros. / Wonder: Bullet Bill appears as enemy/power-up.
• Super Mario Maker 2: Placeable Bullet Bill launcher/cannon.

Clarify which game you're asking about for cheat help.