number #1 cylinder misfire,check engine light is on on 1999 Mitsubishi Eclipse

replaced coil pack,wires,and plugs.still number #1 cylinder misfire,also replaced caytalic converter

2 answers
You need to perform a mechanical check of the #1 cylinder to make sure it is OK, you could have low compression in that cylinder, you could have an injector that isn't firing, and there is a possibility of an intake gasket leak. Learn more here: http://repairpal.com/OBD-II-Code-P0301
problem with EGR can cause this also