Metering actuator issue

[Scoot5869]

So the other week my truck started to stumble and run rough at the end of the day no code came up. I hooked to insite had a couple codes on there that came up one for 2215 and 2313. I ran the cut out test and everything ran fine. Nothing shut down cylinders all sounded good.this fall I replaced all actuators bc one was bad so I just did them all. The ifsm had a hole that ended up being slightly stripped but I used longer bolt and it worked for a while the then rear M actuator started to seep. So I just assumed it was getting air in somehow and went ahead and replaced ifsm got it all back together truck ran great problem solved. Went to go run a load and made it to terminal and she stumbled again. Got load and about two miles from home she just runs like shi#t again had codes on dash this Time. Pulled code and 2313 was there again so I did cut out test and it died on back three cylinder. So seeing as that one leaked on old ifsm I replaced it.
Put new one on truck ran great bobtail. Go put empty trailer on go two miles down rd same damn thing happens same code too. Now I’m thinking it’s maybe in the harness I’m goin to check ohm on things tomorrow. Is there any places these things are known to break at ?got quoted 2000 for a new harness worst case situation. I know things get brittle with heat and age and those connections have been off many times now. Thanks for any suggestions