Car running rough and no power

My car all at once started running rough and it lost power. Engine lights came on so i checked the codes and this is what i got; P0300 p0304 p0305 p0306 p0356. So this is what i have done so far;I check the power to each coil # 4, 5, 6, and i used a noid light and check all three coil plugs for a pulse signal. All checked out good.. I could not find any vacuum leaks. So i am not sure what else it could be unless its injectors or a fuel problem.