From Halopedia, the Halo wiki
Within the Halo 2 disc, modders have found text placeholders for the scripted dialogs at certain parts of levels. Some of it has been humorously altered from the original script, and others depict lines that were eventually discarded.
- Before (After dispatching Covenant boarders en route to the In Amber Clad): "Thanks, Chief. I owe you one. Take me now!" 
- After: "Thanks, Chief. I owe you one."
- Before: "Alright, this is the shit."
- After: "See this look? It's terror!"
- When the player passes through the first room in Please, Make Yourself At Home, Cortana was scripted to say: "Flood spores have contaminated the city's life-support infrastructure - the filtration systems are overloading!"
- When the player first encounters the Flood growth on the walls, Cortana was scripted to say: "The amount of Flood bio-mass is increasing exponentially. There are reports of infestations in every district!"
- When the player reaches the Sanctum of the Hierarchs, Cortana was scripted to say: "The Jackals and Drones have declared themselves the servants of the Brutes. The Hunters have sworn allegiance to the Elites. The Grunts seem to be neutral, or at least afraid to announce which side they support. Except for Truth, the Prophets aren't saying a word."
- When the player takes too long to enter the conduit, Cortana was scripted to say: "I've lost control of the conduit! It's breaking away from the ship!"
- Before: "The Hunters rawk!"
- After: "The Hunters have come to our aid, Arbiter. They will fight by our side."
- Before: "Tartar sauce must complete his tasty condiments."
- After: "The Chieftain must complete his holy work."
- Before: When the screen goes to black, the following words are written: "Tics of black for Marty."
- After: Nothing.