I have a prostar with the n13 motor and hsve been dealing with the 4364 fmi 18 code for the last 3 months which caused other codes to pop up.
Inlet nox sensor
Air control valve
Doc replsced 6 months ago
Exhaust back pressure valve
can an exhaust manifold leak cause this code as the tech mentioned there might be an exhaust leak on 6 but they never pursued it any Further.
this code popped up in flagstaff az And this isn’t the first time it happened over here and I’ve read post about flagstaff being a problem for them and this code as well on Detroit motors. It also loves to pop up on Monday’s and then go away after the truck does successful regens.
any help would be appreciated before I go find a non def truck.