I DROVE THIS VEHICLE CROSS COUNTRY, WHILE TOWING A TRUCK ON TRAILER, BACK WHILE TOWING A TRAILER, AND AGAIN WITH A U-HAUL FROM LAS VEGAS TO VIRGINIA (UP STEEP GRADES, AND THROUGH THE MOUNTAINS, ENGINE UNDER QUITE A LOAD, WHILE IN THE SUMMER, USING A/C) I GOT A HEADACHE AND NAUSEAU. MY DAUGHTER AND NEPHEW, WHO WERE PASSENGERS, DID AS WELL. I GOT SLEEPY BEHIND THE WHEEL (THIS DOESN'T HAPPEN TO ME AND HAS NEVER HAPPENED TO ME). YOU CAN SMELL THE EXHAUST. I INSTALLED A CARBON MONOXIDE DETECTOR, AND IT HAS GONE OFF TWICE. FORD HAS DONE SOME "FIXES" INCLUDING REPROGRAMMING A/C. WELL, IF YOU USE THE BUTTONS, INSTEAD OF THE TOUCH SCREEN, YOU CAN UNKNOWINGLY OVERRIDE THIS REPROGRAMMING. THEY DID NOT TELL ME THIS. I GO THROUGH THE GEARS IN THE MANUAL MODE AND DRIVE THIS HARD. YOU CAN STILL SMELL EXHAUST AND GET SYMPTOMS. BORROW A FIRE FIGHTERS "SNIFFER" AND DRIVE THE VEHICLE HARD AND WATCH THE READOUT. IT CANT POSSIBLY TAKE THIS LONG OR BE THAT DIFFICULT TO RESOLVE THIS INVESTIGATION. YOU CAN EVEN PUT A CARBON MONOXIDE DETECTOR IN THE VEHICLE AND WATCH-SIMPLE. GO THROUGH THE GEARS MANUALLY, RED-LINING THE VEHICLE YOU WILL GET THE SMELL AND SYMPTOMS. DRIVE THE VEHICLE HARD UP A STEEP GRADE, YOU WILL GET THE SYMPTOMS. TOW WITH THE VEHICLE UP A GRADE, YOU WILL GET THE SMELL AND SYMPTOMS, ALL WITH A/C ON RECIRCULATE. LESS SO WITH OUT IT BEING ON RECIRCULATE. THIS HAS HAPPENED FORM THE FIRST TRIP OF 09/07/2015 TO CURRENT.