please take time to read the link i posted it explains everything about the ffv. as much as possible use only one brand of fuel and when refilling be sure to drive it not less than 7miles. try to research also if there's a tsb for that, the tsb can only be addressed by computer reflashing (subscribe to alldatadiy.com for more info about your vehicle). i'll try also to look for myself when i get the time. don't depend too much on casa they still have a lot to learn about the car they are selling (LOL).
BTW when you scan the pcm, pay special attention to the long term fuel trim (LTFT) a good trim is plus or minus 10%