Plutonium

all i know is that i lag all the time even in custom game. It's my frames idk how to fix it.

So every time I go to play BO2 on plutonium, I lag bad and my ping is terrible. I do not understand why my ping and game is so laggy. I play other plutonium games such as WAW, MW2 and MW3 and the game runs smooth and perfect I never lag at all, the game plays smoothly. I only own BO2 on plutonium as well no other place. Also I can play BO1 on steam and I have no lag and a great ping. Can someone please help me? Black Ops 2 is literally my favorite COD game and console have a ton of modders.