Hesitation when cold

I have a '96 VW Passat w/VR6 5 spd. When the engine is cold and under load it hesitates badly. The check engine light came on w/PO300.PO301,PO306 which were multiple misfires and specific misfires. I change the plug wires and the coil pack (the coil pack had corrosion on it). The car runs much smoother however I still have the hesitation when cold but the engine light does NOT come on anymore. So I guess I have fix at least one problem. When cold the engine idles smooth and if I let it warm up for a minute or two everything is fine. What else should I look at?