2003 Ford 6.0 Mileage Drop, help?
The other night my truck digital readout that had read 13.5mpg for the longest time went down to 11.2 and has gone up to 11.5 but not higher. I recently changed fuel filters, oil fliter, ball joints and wheel bearings(and although not that it would affect mileage poly bushed the whole truck, ugh). I thought it might have been the station i fueled up at and we had a lot of rain that week, but have since ran diesel from a station that I use a lot and nothing changed. Any ideas? Worried the PCM might be faulty. Any way I can check that without subjecting myself to a dealership visit? Any help is greatly appreciated...