What do you recommend checking for rough running and idle and no power 2004 Kia amanti

Hello, so many things can cause this, and you don't know until you perform needed testing. Engine performance issues can go from a restricted exhaust preventing performance, to a fuel delivery concern, air intake restriction or leak, vacuum leak, ignition spark issues, emission control components -- it's just too hard to know. Have troubleshooting performed using a proper diagnostic tool that can monitor data and using shop manual information as a reference.