As mpolli said the spark plug connectors are a problem area. The short ones underneath the coils. Could be a bad coil too, but this is an easy problem to track down. Look at your codes and it should tell you which cylinder is misfiring.
Once you determine which one it is then switch the connector with a different coil and see if the misfire follows it. If it does you found it. If not try switching the coils. Good luck.