have you tried spraying the mass airflow sensor with electric motor cleaner. you may want to try that. mine was having the same problem and i tried all sorts of things and it turned out my MAF sensor was dirty. all i did was take the metal cylinder out of the air filter box that the mass airflow sensor was connected too. and sprayed the little sensor inside with the electric motor cleaner. try this and let me know how it works out for you. if that doesnt work then im as stumped as you are.
