Hey you can host online but not on your jtag but with system link and infecting your self with the mods heres a tut:
Equipment Needed:
MW2 COPY FOR XBOX 360 MAKE SURE ITS CLEAN AND HAS BRAILY ANY SCRATCHES
XEX MENU ANY TYPE 1.0 OR 1.1
JTAG XBOX 360
RETAIL XBOX 360
2 ETHERNET CABLES AKA CAT 5 OR KAT 5 CABLES
AND AN INTERNET CONNECTION DUH
LABTOP OR COMPUTER
AND A PATCH WITH INFECTIONS AKA MOD MENU WITH INFECTION MENU IN THE MOD MENU!!!
LINKS ARE BELOW AFTER THE TUTS!!!

NOW LETS GET STARTED:

1) SET YOUR 2 ETHERNET CABLES TO YOUR ROUTER OR MODEM
2) TURN ON YOUR RETAIL XBOX 360 AND YOUR JTAG
3) HAVE YOUR JTAG HOST THE GAME THEN YOU JOIN ON YOUR RETAIL
4) IF YOU HAVE MY PATCH GO TO IT WILL SAY WAIT FOR THE HOST TO VERIFY YOU AN MAKE SURE TO GO TO PLAYERS ON THE MOD MENU VERIFY AND GIVE ALL THE OTHER OPTIONS ADMIN AND SO ONE THIS IS DONE ON YOUR JTAG
5) THEN AFTER THAT ON YOUR RETAIL YOU SHOULD HAVE THE MOD MENU GO TO INFECTIONS THEN INFECT YOUR SELF WITH ALL OR ANY THEN THERE WILL BE A DVAR OPTION TO ADD EXTRA THINGS TO THE INFECTIONS YOU ADDED THE INFECTION DOES HAVE A 10TH LOBBY IN IT SO YEA HOPE THIS IS SIMPLE
6) AFTER THAT QUIT HOST A LOBBY THEN THERE
7) FOR THE TENTH LOBBY JOIN A PUBLIC GAME AND KILL YOUR SELF AND INVITE FRIENDS THEN THERE YOU GO SO YEA
8 OPINION DONT HAVE TO DO THIS STEP) BUT YOU CAN HAVE FUN IN PRIVATE MATCH TO
9) YOU ARE READY TO GO
10) HAVE FUN
11) OH CANT BELEAVE I LFET THIS OUT MAKE SURE TO INSTALL MW2 ON YOUR HARDDRIVE WITH XEX MENU!!!! AND HAVE FUN
12) HAVE MORE FUN!!!!!!!




HOW TO INSTALL XEX MENU WITH CD:
1) INSERT THE DISC SHOULD ALREADY LOAD UP
2) PRESS Y THEN GO TO THE CD
3) PRESS Y ON THE C0DE9999 FOLDER AND COPY IT
4) GO BACK TO HDD1
5) GO TO CONTENT AND GO TO THE FOLDER WITH 16 0'S
6) PRESS Y AND PASTE
7) GIVE YOU AN SLAP ON THE A$$ AND SAY THAT WAS EASY
FINAL STEP) HAVE FUN




HOW TO INSTALL MW2 TO XEX MENU

1) MAKE A GAMES FOLDER IN XEX MENU BY PRESSING Y AND CREATE DOES NOT MATTER WHERE YOU CREATE THE FOLDER
2) THEN IN THE GAMES FOLDER THAT YOU CREATE MAKE A MW2 FOLDER INSIDE IT
3) AFTER THAT GO INTO THE MW2 FOLDER AND COPYDVD BY PRESSING Y
4) COPY IT THEN IT SHOULD A GOOD 10 TO 30 MINS BUT IF ITS REALLY SCRATCHT IT WILL JUST BACK OUT AND NOT COPY THE REST OF THE FILES
5) THEN JUST LAUNCH DEFAULT.XEX OR DEAFAULT_MP.XEX
6) HAVE FUN



HOW TO PUT THE PATCH ON XEX MENU

1) THERES ALOT OF DIFFERENT WAYS THIS WAY I WILL BE USING A TRANSFER CABLE
2) GET THE JTAG HARDDRIVE THEN PUT IT ON THE TRANSFER CABLE
3) HOOK IT UP TO YOUR COMPUTER OR LABTOP
4) OPEN XPORT 360 OR XPLOER 360
5) GO TO DEVICE ON PARTION 3 THEN GO WHERE EVER YOU PUT YOUR GAMES FOLDER WITH MW2 THAT COULD BE THE ROOT OR IN CONTENT OR ANYWHERE IT DEPENDS ON WHERE YOU PUT IT AND MADE IT
6) THEN GET THE PATCH I SUPPLY YOU OR ANY OTHER OPEN THE GAMES FOLDER MW2 THEN YOU WILL SEE ALL THE FILES THEN DRAG AND DROP THE PATCH INTO THE FOLDER THEN THERE!!!




HOPE THIS WAS HELPFUL
HERE ARE THE FILES YOU NEED TO PUT IN YOUR MW2 FOLDER IN ORDER FOR IT TO WORK
HERES THE PATCH_MP.FF: [ Register or Signin to view external links. ]
DEFAULT_MP.XEX: [ Register or Signin to view external links. ]