Thanks but I have been having this problem for a long time and have tried a number of things,I have cleaned the egr the day before a trip, fuel filters, airfilters,etc. Is it possible for the turbo to just stop working because that is what it feels like, When I am in the coastal mountains that are not very high but very steep the truck pulls great but as soon as I get in the higher stuff it starts acting up , it will go from 55 down to 20mph fast , there have been times when I thought I was not going to make it over.