And it's a 2012 6.7 by the way

 

That's usually due to breaks in the harness or an open circuit. If tested all good the codes may take a couple times to clear. Try some dielectric on the connections.

 

Ok thank you I will try clearing the codes a couple more times I will update what happens. Thanks

 

You may want to test the harness again with a multimeter and attempt to wiggle it in several different places on both banks while someone is watching the meter. Look for resistance to change to OL.

What I’m getting at is if you are testing the harness as the truck sits, the open may not appear. If the code is coming back when you drive it’s because vibration is causing the open. This is a common process we do on aircraft to find intermittent shorts where intermittent faults occur only in flight.

 

Yeah well it's crazy because number 7 has popping up for a couple months now all the sudden the number 4 is popping up and the whole motor just got rebuilt back in March so I'm starting to wonder if they messed up the harness some how starting to think about running my own wires to the glow plugs. Thanks for the info

 

Well check engine light is off just cleared codes a couple times and all is good thanks for all help greatly appreciate it.