2003 Ford Focus misfires

Engine Performance problem
2003 Ford Focus 4 cyl Front Wheel Drive Automatic 87k miles

once engine warms up it starts to misfire and to a
point to were engine quits replace crankshaft sensor
& coilpack compture codes of 2cyl misfire & 3 cyl misfire then finally random misfires engine cools for a
while and runs fine for a good while then starts to
misfire again sparkplug wires are good7