This tutorial will tell you how to force host in MW3 and BO2. FWI BO2 version of this works for me but may not work for you.
Ignore the - that just is the the line between both tutorials if there isnt one that means its the same thing.
You will need:
-Latest MW3 Patch
-Latest BO2 Patch
-An OPEN NAT
-Cheat Engine
1.Boot MW3 and Cheat Engine - Boot BO2 and Cheat Engine
2.Attach Cheat Engine to MW3 -Attach Cheat Engine to BO2
3.Click Play and wait to get connected.
4.Once connected, search for a TDM Match
5.While the game is searching, quickly write 8 in the search field of Cheat Engine and hit "First Scan". Make sure you dont enter someone else's lobby. If it happens, try again.
6.Once Cheat Engine is done searching, back out from lobby in BO2 or MW3 and search for a FFA match.
7.When the game searches, quickly write 4 in Cheat Engine's search field and hit "Next scan". Again, make sure you dont enter someone else's lobby. If it happens, restart from the begginning.
8.Once Cheat Engine finishes the search, repeat,6 and 7 until you have a low amount of address found.
9.You should have 2 static (green) address in the list that changes to 8 if in TDM and 4 if in FFA. One of these 2 controls the minimum required players in the lobby before the game's start. Mine is 05AA35F8. Change the value of the address and freeze it to 1. This will make the game start as soon as you search for a game mode.
Enjoy being host!
P.S. if you do not wish to freeze, simply change the value to 1 when the game is looking for a lobby.
Credits:
Hoot14, Jordnel, and NightmareXx (I didn't know you founded it DX)