There isn't one answer for a misfire. The cause could be a clogged fuel or air filter, a faulty spark-plug, faulty injector, faulty coil, water in the fuel, or a fuel pressure issue. Diagnostics will need to be run to narrow the problem down to the source.
change spark plug and wire. If persists, check for gasket leak and leaky fuel injector. Also check power coming from the coil pack with an ohmmeter or test light.