Halo 3 coop unplayable (stuttering)

Hello,me and my friend wanted to do all Halo campaigns in coop. Well Halo CE and Halo 2 was a okay experience,we had input lag but it was fun. But Halo 3 is simply unplayable,it stutters every 2 seconds and we cant play like that. Any fixes or a way to reduce this stutter?