Rough starting, text shows missing on all 4 cylinders, runs fine after warm up on 2002 Kia Spectra

Plugs and wire have been replaced. The coil packs and the valve cover gasket leaks are suspect but the auto parts store suggested changing the fuel filter first. Only thing is the fuel filter on the Kia is very different from the one the auto parts store shows I need. The one from the store has 3 hose connections and the one on the KIA only has 2 hose connections. What's going on with the strange fuel filter?

Asked by for the 2002 Kia Spectra
I wouldn't change the fuel filter first. The codes are for a misfire. Lift up the ignition coils and see if oil is leaking down into the spark plug tube wells, if oil is leaking down to the spark plugs replace the valve cover gasket and tube seals (easy job!), clean away the oil deposits and see if the misfire goes away. You first need to track down the source of the misfire. A restricted fuel filter would most likely cause a loss of power on acceleration.