WTF? Fuel injectors gone wild

[Joenavy85]

I don't know what's going on with my fuel injectors (at least i think it's my injectors). For the past 4 tanks my ultragauge has been pretty accurate (within .2 gallons when i fill up) but today i filled up at the end of road trip and it was off by 1.6 gallons (in my favor). i had a feeling it was going to be off since there was a noticeable difference compared to my gas gauge. looking at my gas gauge i estimated that i had used 12 gallons, and my fill up was 12.2 gallons, but my ultragauge said i had used 13.8. any chance that one of my injectors isn't working properly therefore i'm using less gas than the ultragauge thinks??

[Mustang Dave]

Did you do more than usual DFCO (on downgrades) on that tank? The UltraGauge will display greater than 0 GPH in DFCO.

[Joenavy85]

no more than usual, i usually put it in Neutral when i coast, on the rare occasion i leave it in gear when going downhill (steep hill, to control speed)