I played every CoD since MW2 and I fucked around with CE and some prestige hacks, I never got banned. So If you don't exagerate and make it obvious you hacked your rank or unlocked some things I guess you're safe. Or maybe I just got lucky...
I think if you use wall hacks, aimbot and shit like that you have way more chance to get caught one day or another, people gonna report you, some investigations will be done and the ban will come....