1994 6.5 TD limp mode under hard throttle only
 

So for the last several years I have had a problem with my K3500 6.5 TD going into limp mode ONLY when I accelerate hard pulling my big enclosed race trailer or when pulling out into traffic, I put it in neutral shut it off and restart and all works good until I mash on the throttle again, seems to be anything over 3/4 throttle, it is pulling code 36 and 41. The truck starts and runs great with no issues except for the limp mode issue, I have new batteries,all grounds have been cleaned installed contact washers, I replaced the PMD less than 500 miles ago and relocated behind license plate, the truck has been serviced religiously since day one, I had a new IP installed at 198000 and now have 261000.