I'll start with the symptoms:
-Rough cold start, even when plugged in. It seems to shake and miss for a few seconds and then clears up and idles fine.
-Bad miss until warm. If I try to drive it before temps hit over 100*, it will start to miss real bad at around 1500 rpm's. Even with your foot in it, it's almost impossible to go over 35 mph.
-No codes until a few days ago. Starting last weekend, I am getting intermittent codes. Sometimes a P0306. Sometimes a P0300. Sometimes neither. Sometimes BOTH. (P0306, Cylinder 6 Misfire Detected. P0300, Random Cylinder Misfire Detected.)
-Sometimes I can hear the injectors buzzing real good when I turn the key on. Other times, I can hardly hear them at all.
With everything that I have read, it seems to point to a bad FICM. However, my FICM voltage never drops below 47.5 and usually rides between 48.5 and 49. Battery voltage never seems to drop below 11-11.2 during cranking.
With all that being said, there are some heavy zip-ties that are running around the FICM. It leads me to believe that someone possibly broke the clips off of the plugs.
Is it possible that one of the plugs has loosened up? Would that lead to the symptoms mentioned above?