Ford Repair: FlexFuel (85% Ethanol), ford taurus, ford dealer


Question
I'm driving a 2003 Ford Taurus in excellent condition. Last month I had a 60,000 mile work-up performed, including tune-up, etc. My car gets oil change special every 3 months, no exceptions.
Two weeks ago, I decided to try (cheaper) FlexFuel after being told by station manager that my car can handle it. The next day, I noticed "Check Engine" icon and drove to the Ford dealer. Service manager told me that the problem was probably new fuel use...I should wait until I'm down to 1/4 tank left...fill it up again with FlexFuel...the warning should go away, but if not then I should disconnect battery and that would be it."
I did exactly what I was told, including disconnecting battery to get rid of the warning icon.
However the next day the warning icon was back and the car idled "funny" i.e. wasn't running steady as usual...I felt like it may stall on me while I was driving...something was not right. Now I am worried that I may wind up spending a lot of money because of my stupid decision to change fuel! Please advise.

Answer
Alex,
You can go to www.gm.com, and read about gms new fuel for their vehicles. Looks to me these vehicles, 2006 or newer are designed to run on this fuel. I bet your vehicle isnt designed to run on this fuel, now with a check engine lite you could have more then one sensor that is bad on the vehicle.. I wouldnt dump anymore of the flex fuel in your vehicle... Thanks..