OBD-II Code P2433 is defined as a Secondary Air Injection System Air Flow/Pressure Sensor Circuit
The Secondary Air Injection System (AIR) pumps outside fresh air into the Exhaust System during cold engine start up. This additional air helps burn up the highly rich exhaust emissions that are produced when the engine is warming up. The engine computer (PCM) uses a AIR Pressure Sensor to monitor the functionality of the AIR system. If the AIR Pressure Sensor sends back an implausible signal, code P2433 will be stored. On some vehicles, the Pressure Sensor is part of the AIR Control Solenoid.