I have an 8.1 in a 2004 motorhome. just replaced fuel pump and filters plugs and wires. took it on a 400 mile trip and check engine light came one about halfway for a knock sensor.
cleared the code and drove rest way no problem. on the way back about 100 miles the light came back on for same sensor cleared it and kept trucking. about another 150 miles it started a small miss when going up a hill and would smooth out on level ground. then it started to do it more and more. its not like a plug or fuel miss its more like you turn key off and back on. no check engine light and you can stop and turn ignition off and start it back up and it runs good for little ways then starts it again. I need some info

 

I would think,clean the MAF properly,for a start

 

I will try that