ISB6.7 DEF HELP

[lastmanstandin31]

I appreciate the advice and unfortunately I can not afford to replace all the stuff on this truck. I did replace all DEF lines, doiser unit, DEF filter and flushed everything best that I could with about 20 gallons of DEF fluid and had the DPF filter baked by fleet products. Problem is def system will not prime half the time and throws pressure codes and def input line codes every day which derates the truck. I can clear codes with insite and run the truck again until it derates again. I have spent thousands. Unfortunetly I dont believe anyone can prepare for somebody destroying there truck for no reason. We have no idea who did it or why all I know is I am doing exactly as you said and taking the matter into my own hands and believe learning how to axe this mess at this point is my best option to avoid any more costly parts and time down. Once again thanks for the advice.