Requesting help for troubleshooting codes

[Ngkx535d]

So I have the following codes:

452A - Particulate Filter system
478F - low press exhaust gas recirculationvalve, plausible.
47C9 - low pressure exhaust gas actuator pod control.
4D6C - exhaust gas temp sensor before particle filter.

Problem is, I get no boost or power past 3k RPM, and when I attempt to push past 3k RPM, I get an engine malfunction/reduce power message.

I’m not worried about the 452A code as I monitor regeneration via Carley and the system operates as advertised (I figured out months ago by reading this forum to replace the thermostat).
I removed the manifold and cleaned it out (wasn’t really dirty) and placed everything back together today. Still the same issues.

I don’t want to throw parts at it, but I ordered a pressure converter after reading various posts/threads on this forum (part number 11747805391) but I’m curious to know if this is a good start.

Also - can somebody tell me where this is located lol???

Thanks for any help.
-Nick