My sister has a 2011 town and country that already had the front head replaced due to the multiple cylinder misfire codes. Now it will occasionally run very rough (shakes the vehicle) with the service engine soon light flashing and then have multiple cylinder misfire codes on the front cylinders. It happened last fall and again in the last month or so. I don't have the exact codes that were displayed the last time, I will add them if she provides them. Any ideas? She needs it solved so she can trust the van. Taken it to dealerships and they have no idea and neither have local mechanics. She is close to trading it off and buying a Honda or Toyota.