On the 2003 Toyota Celica, P0441, P0442 and P0446. Most commonly when these 3 are set together, it’s a Vapor Pressure Sensor.
DTCs P0441 and P0446 are recorded by the ECM when evaporative emissions leak from the components within the EVAP System, or when there is a malfunction in either the VSV for EVAP, the VSV for pressure switching valve, or in the vapor pressure sensor itself.
DTC P0442 is recorded by the ECM when evaporative emissions leak from the components within the EVAP System, or when the vapor pressure sensor malfunctions.
So, with that said, on this vehicle, when all 3 of these codes are set, the most common problem is a faulty Vapor Pressure Sensor. Best bet at this point would be to have the EVAP System “smoked”. This is where a machine forces smoke through the system. If there is a “minuscule leak somewhere”, it will reveal itself with a stream of smoke. If the smoke test proves there are no leaks, then the Vapor Pressure Sensor is the most common culprit. Carefully inspect the electrical connector for any loose, broken or damaged wires. If the visual inspection checks ok, replace the Vapor Pressure Sensor. You can find the VPS located at the top of the fuel pump assembly. You can access the VPS by removing the rear seat.
Does your vehicle have a similar problem? Get connected to a Live Q&A session with a certified Auto Mechanic and get your answers on this problem now!