Hello Jeff !
Have you cleaned the fuel injectors? If you have a slight misfire that hasn't turned the service engine light on yet you possible just have a few lean injectors, Also I would clean the mass air flow sensor with a mild injector spray cleaner. Spray the small wires off inside the sensor. That is the best place to start on this kind of problem. Also have you changed the fuel filter? possible needed it will cause a lean condition. Hope this helps.