05 cumming 5.9 missing at idle, truck runs great otherwise and getting 21-22 mpg

I changed the fuel filter and run additive on a regular basis

I added 2 cans of seafoam on my last tank of fuel, ran that thru still the same issue

I scanned they system thru the OBD2 port and I have no codes



My wife is taking the truck pulling a horse trailer and 2 horses next week, she is going 3k miles trip

Goob