jeevankrish

Guys please help. I am extremely tired and helpless. After oil cooler seal replacement, everything looks good and car starts, but getting an error code P0234 & P0471. Cleared code, buts comes back. Some uneven noise when I raise engine and release. Turbo actuator seems to adjust to the change. Not able to figure out. I hope I did not screwup the turbocharger... Also if I am not able to figure out the problem, please suggest path forward.
After removing a ton of soot, is it blocking something ? everything seems clean.
P0234 - turbocharge/supercharger overboost condition
P0471 - Exhaust pressure sensor A Circuit Range/performance
14A900 - The upper limit value of component 'B 60 (Exhaust Back Pressure Sensor)' has been exceeded. DTC Status Current
159300 - There is an internal fault in component 'B 60 (Exhaust Back Pressure Sensor)' DTC Status Current
I replace the sensor on EGR as I broke it during removal of turbocharger. Is that an issue... Also I am not sure how the exhaust circuit works. Will there be leaks in the manifold gasket that could be a problem ?
Over and above bad NE weather is screwing my life for over a month.... Any help appreciated. Thanks.