Help! Engine derated to 25% and won’t start!

[Lonestar10]

always keep def full stop for fuel stop for def the longer the DEF tank is below full the more time crystals have to form in the tank which can cause anything that moves to become stuck and anything that filters to become plugged.

DEF is nasty in non liquid form as basically its water and nitrogen fertilizer mixed together same exact thing ethanol plants do mix nitrogen "UREA" and water and send it to the fermentation tanks to give the yeast nitrogen to help break down sugars to ethanol. just DEF is filtered of dirt and waterborn contaminates.