What if you have changed all of your coil and plugs and still have a misfire on 2006 expidition?

WOW Sounds like you spent alot of money. First lets get you on the path of saving some of that money. Go online and look up AUTEL Maxiscan MS300 OBD II code reader. This is a relatively inexpensive (less than $50.00) scanner and it works very well for most home uses. You need to determine which cylinder has the misfire and if it is above or below 1000 rpms. Once you know that you can troubleshoot the coil and plugs by simply taking the suspected bad one and put it in a different cylinder to see if the misfire moves to that cylinder. It's cheaper than replacing all of them. If you know it is not the spark plug, coil or the spark plug boot the next thing to check is the wire bundle connectors to the coil packs.

A misfire is not a killer so you have time to wait for your scanner to come in and go from there. That scanner can save you and your friends and family a ton of money. Well worth it. Good luck.