Addressing the random or multiple misfire codes on your Honda or Acura

Anyone who's worked on a Honda, or owned a Honda or Acura may have experienced a random, or multiple misfire codes when the car may feel fine, or may have one cylinder misfiring. It is common for Hondas or Acuras to show multiple misfire codes, even if just one cylinder is misfiring. You may see P0301 all the way through P0306 (for the 6 cylinders) and wonder "how can all of my cylinders be misfiring?". If that were the case, the engine wouldn't even be able to stay on. 

In this case, the easiest thing to do if the vehicle is misfiring, is to unplug each ignition coil while the misfiring vehicle is idling. If you unplug a coil, and the misfire gets worse, that means that the coil and spark plug are both good. If you unplug the coil, and there is no change, then the problem is either that coil or spark plug. Very easy right?

Sometimes the computer can get a little buggy, and you may see a misfire code just randomly. Just reset it. If it comes back, it's time to do a full tune up.  As the owner of a Civic, I've started the car one morning, and the check engine light came on showing P0300, P0301, P0302, P0303, P0304. I thought to myself "what the heck?" I've never felt a misfire. Cleared the codes and have been good ever since. 

If you don't have a scanner to clear the codes, you can always unplug the battery for at least 45 seconds. Just make sure your radio doesn't have a security code on it!