I just got back from towing a trailer to and from FL, about 7,000lbs. Truck ran great and got somewhat normal fuel mileage for winter mix and the new Ultra-Low sulfer diesel, which I dont like -:t. Since I have been home my truck as slow started to get VERY bad fuel mileage. No loss of power, no abnormal smoke, and motor runs good. I had a buddy of mine check fuel rates and all the good stuff and they were all good. No "Check Engine Light" was on but there was 2 codes in the computer. P0236 and P0101, MAF Sensor out of range and Boost Sensor out of range. Replace both sensors or is one causing the computer to see the other screwed up?