Engine Light trouble code

Hi Roy, We do plan on taking the car to another mechanic, but it won't be for a couple of weeks. We're fulltime RV'ers (towing the Hyundai) and presently in GA heading for FL.Once we get to FL we'll be staying put for a while and have it diagnosed. FYI: It has been to THREE Hyundai dealers in the last 3 months and no one (Ocala, FL - Chattanooga, TN - Goshen, IN ) could give me a definitive diagnosis. All they could do was start replacing parts and hope they find the right one! We've already spent hundreds of $$$$$ replacing the fuel filter, fuel pump and camshaft sensor. Can you suggest how to find an expert emissions tech? Haven't had much luck with Hyundai service as yet. Thank you for your response. Joe