My 2002 Taurus SES Duratec is getting P0316 (Misfire detected) & P0301 (Cylinder 1 Misfire) codes. While driving it misses allot. I checked for vacuum leaks. Changed the plugs about 5000 miles ago. Any ideas???

 

Check the wires and plugs again. If number one plug is misfiring, you need to replace it again. Replace the wires with either Motorcraft or a high quality aftermarket brand. Cheap wires are just that. Also replace plugs with Motorcraft.