First off I just joined, but have used info from here many times over the years so thanks. I have a 2003 F150 5.4 that had a coil going bad, but did not throw a code. I bought a set of 8 coils of ebay for $50 and changed all out including new Motorcraft pulgs. Truck runs great and does not mis-fire at all, but now when I am sitting in park at idle for several minutes the truck just shuts off. No rough idle or warning just shuts down. I looked under the hood to make sure I had all the coil plugs correct/hooked up and noticed I had left off a vacuum hose and thought that must be the issue, but it did the same thing this AM. Now the CEL came on. Any ideas? Do I need to unplug the battery to reset the CEL after changing all the coils? I am going to go to Adavanced and have them code it out when I leave work. Just curious as to what this could be. Thanks in advance.

 

You won't have a clue till you have the codes. Do NOT disconnect the battery or the codes will be cleared.