I have a 1998 Ford Expedition. It has 97,000 miles on it and I have had very little trouble with it. I bought the truck new from the factory. I have taken very good care of it. After a trip on the expressway (30 mins.) I pull into my mothers driveway and the check engine light comes on. It did this a few years back and I put some gum out in the tank and the light went away. I did the same thing this time except now when I come to a stop or I am at idel, the car sounds like its missing. Even while driving the engine seems to be mis-firing. The light is now always on. When pulling a trailer or driving regular everything seems fine. Any ideas? It has stalled a few times when pulling up to a red light. I ran codes on it when I got home from my mothers and got codes p0171 and p0174 they come out to be that the fuel system is lean? Whats my first step? Thanks
-Ben Its got a ruff idel, some times rises to 1500 rpm.