Originally Posted by RamTech
That's the intake air temp sensor. While it does need to be plugged in and working, it won't cause a cylinder specific misfire. Since you seem to have checked the plenum pan visually through the throttle body, I'm posting the diasgnostic for this as Chrysler recommends. One other thing - try removing the serpentine belt and running the engine and see if the problem goes away. It's rare, but I have seen a perceived misfire turn out to be an accessory problem.
I found it interesting because I can't find a connector for it anywhere in the engine bay.
I'll be removing the belt in the next 20 minutes then, will report back.