CM870 High Pyro/Low Boost intermittent under load

[nmazpeterbilt]

WE have still been fighting with this. There isn't an issue until ambient temperature gets over 90* then the hotter it gets the more we have it. It is a mechanical pyro. There was an issue with the turbo actuator, we had that replaced. Replaced the sensors mentioned here and had EGR checked. Can't figure out why it is doing this. Have had mechanic in the truck with Insite and never can figure out what it is doing that is causing this.