Troubleshooting help

[big_roy]

I've got an 08 CM871 Serial#79252599 485/1650 W/@m*m^2 and it keeps throwing fault code:
0629 - Turbocharger 1 Compressor Intake Pressure - Data Valid But Below Normal Operating Range - Moderately Severe Level
It comes and goes at random it seems like. Before this last round of tinkering there were 226 counts.
I've also had 70 counts of 2288 Turbocharger 1 Speed - Data Valid But Above Normal Operating Range - Least Severe and 13 counts of 3348 Turbocharger 1 Compressor Intake Pressure - Data Valid but below normal operational range - Most Severe Level

So far I've changed ALL the engine and turbo sensors, new air filter, and tried swapping with another known good ecm. Any help/ideas would be greatly appreciated.