Exhaust Back Pressure at Idle . Turbo boost spiking

[windowrattler]

So one of the main goals of the engine is to keep the aftertreatment up to temp. To do this it will "choke" up the turbo to create boost to help create heat. I think I'd take a look at some of the temp sensors in the aftertreatment. Not sure where youre located but it's cold up here so maybe what it is doing is what it actually is supposed to do?