I asume you are talking about a CoD lobby and I wouldn't recommend it on Xbox has they are hot on banning people who do. However, Ps3 is not and so I have hacks and mods on there. If your very desprate try 'googleing' Derek-trotter. :)
How do I create my modded lobby on gears of war 3
you have to get in a modded lobby
No, You cant even Play on xbox live with a modded xbox 360 or modded game
You got deranked.
Usually Ground war because there's the most people in one lobby. But sometimes free for all because a lot of people go on that section. But there is a very low chance that you could find a modded lobby, it's really rare. Hope this helps :)
Unless you are in a modded lobby...you cant.
its like what normally happens though if you stay in that lobby for 14+ hours you may have a problem
its probably modded or hacked or banned.
To start a challenge lobby a JTAG is needed a Jtag is a hacked/modded xbox it ranges from $150-$500
you can go the tech game.com and get som mod on a lot of game
Create a private match and invite friends. Feel free to tweak settings. Or, you can host a modded lobby.
Its a viral :D So basically join a game a private match with slow mo on and then host ur own modded match :)