I have an 08 5.4L and installed the Edge tuner last week. Since that time, I have noticed that the engine will misses sporadically...typically at lower RPM's or upon acceleration. It is very random...may happen once every few days, and lasts for 30 seconds or so, then engine is fine. The only changes I have made to the truck lately are the Edge and a Banks Monster exhaust. With the Edge, I am running the canned Level "2" program with 87 octane and no custom settings. I did run it on level 3 with 93 octane a few days ago, but reverted back to level 2 and lower octane. Any ideas on the missing?

 

First of all i have the exact same edge evolution tuner and love it (knock on wood since i havent had any problems yet.) This sounds kind of like a problem i and a buddy had on our 5.4s, not exact, but kind of so ill take a shot.... I was experienceing engine misfire and the like when at low rpms, going up grades (when the engine was under load and lugging basically.) it would not appear as much if i turned overdrive off and/or didnt go on the highway or above 60mph. I was getting super worried about money, if my truck was going to take a crap, and the like when i mentioned this to a guy i work with. I started listing the symptoms and he finished my sentences for me and immediately knew what my problem was. He said he had the exact same thing and just changed out the plug boots (with new springs in them) that run from the coil pack to the plug. So what i did was take all of mine out, inspect them for any noticeable cracks (i found none) so i cleaned up the boots, contact points and springs, put new dialectic grease on them and good as new!! it was amazing to actually try something for the first time and have it work! I know this may not be your problem at all, but a new idea, a place to start looking, or a place to double check never hurt. good luck.