I wouldn't think the fuel level sensor would turn on the Check Engine Light, do you know which code is stored in the engine module?
I would go get a bottle of Chevron Techron Plus and ad it to a tank of fuel, this may fix the fuel gauge sending unit in the tank, I know it sounds crazy, but I just recommended this a couple weeks ago and it fixed their problem, for about $10.00!
Learn more here: http://bit.ly/Techron_Concentrate
Here is part of the letter I received: "I am truly amazed at your answer about the gas gauge fix. I poured the Chevron stuff in the gas tank and the gauge started to respond about five days later. Thanks for the great tip. Now I don't know what to do with my 300 dollar fuel pump/gas gauge I bought for the car"