I posted this earlier today in another area. Thought this area might be more appropriate.

Got a problem. My 06 v10 has 41000 miles on it. It started missing under load when it had ~34000 miles on it. the dealership has tried to figure out my problem and keep coming up with "fuel quality". The codes sent back say "random missfire". The thing is, when this first started I had the filter changed, the tank flushed, and the injectors cleaned and after every time, it would do the same thing. I buy fuel from reputable name brands just to make sure. The last time, they put 10 new spark plugs in it and the miss went away. I filled up with fuel, $75.00 worth, at Sunoco (good enough for Nascar, should be good enough for Ford) and it ran good for ~280 miles. Then it started back missing under load (merging into traffic on the thruway). Ford tells me it has to be fuel related. They changed the plugs again and its OK. Because its "fuel related" they want me to pay some of the cost. They have 20 hrs in diagnostic time, have been on the phone with Ford Hotline, and still I think it will happen again.

Has anyone had this kind on problem?

Also, truck has Banks exhaust on it. The Fuel pressure and sensors seem to be OK.