You would get a different code for an O2 sensor problem.
Your P0234 has nothing to do with the O2 sensors.
28 - DTC-Based Diagnostics / MODULE, Powertrain Control (PCM) / Diagnosis and Testing
P0234-00-TURBOCHARGER OVERBOOST CONDITION
Theory of Operation
The base Turbocharger boost pressure is managed by the mechanical Wastegate. The Wastegate is spring loaded in the closed position. Boost pressure is applied against the spring pressure of the Wastegate to control the speed of the Turbocharger. The Wastegate Solenoid is a Pulse Width Modulated (PWM) solenoid that controls the amount of boost pressure applied against the spring pressure of the Wastegate. The way that this system operates is, boost pressure is supplied to the Wastegate Solenoid through a hose connected to the Turbocharger housing. The Powertrain Control Module (PCM) varies the PWM signal to the Wastegate Solenoid to control the amount of boost pressure applied against the Wastegate. When more boost pressure is needed, the Wastegate Solenoid will direct more of the boost pressure to atmosphere and less against the Wastegate spring.
When Monitored and Set Conditions
When Monitored: This diagnostic runs continuously when the following conditions are met:
•With the engine is running.
•Turbocharger Wastegate Valve control active.
•No circuit faults present for the MAP Sensor, Wastegate Solenoid, Turbocharger Surge Valve Solenoid, or Boost Pressure Sensor.
•The Boost Pressure Sensor actual value, minus the desired value is above a calibrated threshold. The desired value varies depending on driving conditions.
•MIL light will illuminate.
BOOST PRESSURE SENSOR, WIRING, OR RELATED CONNECTORS
WASTEGATE SOLENOID PRESSURE HOSES/TUBES
WASTEGATE SOLENOID, WIRING, VACUUM, OR RELATED COMPONENTS
TURBOCHARGER (WASTEGATE VALVE STUCK CLOSED)