Halo: Combat Evolved - PC XBOX/Cheats

From WikiCheats

Vehicle Cheats

Wall to Warthog On Bloodgultch, drive your Warthog into your base, and get out. Now it should be moving on its own forward. Now you can preform the glitch/cheat. Don't go straight in yet, just in the narrow corridor entrance. Get out, get in front of the wiggling Warthog and make sure you're directly in front of the Warthog (if you're on the side, you'll die). Then you should be pushed throught the wall. The wall becomes nothing and you can fall through the new floor (which is nothing but white)that replaced the wall. You'll die if you go through the floor. Staying in the wall, you can now shoot through the wall you're stuck in and can't die anymore. Patched versions of Halo are probably not going to let this glitch or cheat work, however.