Ever since I bought the truck seems like my boost is low while towing, things ive already done, new fuel filter, cleaned sensor on air box, boost leak test, my truck is stock only has a 4" catback exhaust, so here is the towing scenario... Towing up a grade with 10K toyhauler on manual mode in 4th gear, 2500rpm, doing 55MPH, monitor shows 1300EGT at 15PSI of boost. If I push the truck a bit more to about 2800RPM EGT will go up to 1400 and boost to 20PSI, Im comparing this duramax to my old cummins same numbers but cummins running 1100 EGT at 22-25PSI boost. No check engine light, ive tried slowing down and down shifting and egt's will stay high.