Other Fuel System Hoses Lines/piping, And Fittings problems of the 2015 Ford F-250

This truck has had it's def system malfunctioning from the beginning. It shuts off the engine at random intervals, usually low speed, and displays shift to park. So far it will always restart. It never displayed any codes or turned on the check engine light until recently. When 'check engine' light finally came on, I hoped it would solve the stalling when repaired. I connected a code reader and got code p20ba, which is the def tank heater. The local Ford dealers refused to honor the warranty on this, although it is the emissions system and warranted for 100,000 miles. I had it repaired elsewhere by an ase & aaa certified shop for $400 less than the dealer tried to charge. The mileage is only 60,000. It still stalls even after that problem was solved. It also only gets around 11 mpg when other trucks of the same make and model get around 18. Ford consumer services would not assist me in any way. They gave me a 'record number' or some other useless term like that but no assistance in intervening with the dealer. The def system has never worked properly- no warning of low level or warning of low level when the tank is over 3/4 full, it has been 40,000 miles since I saw the display 'cleaning exhaust filter' and other owners tell me they see it fairly frequently. Neither of the dealerships in my county will help me. It was at mullahey Ford and the only thing they 'found' wrong with it was the fuel reductant heater issue I told them about. I only recently found the article about stalling being investigated by your agency. I have a $48,000+ boat anchor at this point. The vehicle displays no codes yet will not stay running. I believe Ford owes me a fully repaired vehicle because this is all emissions related. I also believe they owe me reimbursement for the repairs I already paid for.