DTC P0451 Evaporative Emission Control System Pressure Sensor: DTC Detecting Condition

WARNING: This page is about a different car, the 2012 Subaru Forester. However, it is still accessible from the selected car via links, so may be relevant.

Detected when two consecutive driving cycles with fault occur.
GENERAL DESCRIPTION < Refer to DTC P0451 EVAPORATIVE EMISSION CONTROL SYSTEM PRESSURE SENSOR , Diagnostic Trouble Code (DTC) Detecting Criteria.>

CAUTION: After servicing or replacing faulty parts, perform Clear Memory Mode < Refer to OPERATION , Clear Memory Mode.>, and Inspection Mode < Refer to PROCEDURE , Inspection Mode.>.

DIAGNOSIS PROCEDURE

Step	Check	Yes	No
1 CHECK FUEL FILLER CAP. Turn the ignition switch to OFF. Open the fuel flap.	Is the fuel filler cap tightened securely?	Go to step 2 .	Tighten fuel filler cap securely.
2 CHECK PRESSURE VACUUM LINE. NOTE: Check the following items. Disconnection, leakage and clogging of the vacuum hoses and pipes between fuel tank pressure sensor and fuel tank Disconnection, leakage and clogging of air ventilation hoses and pipes between fuel filler pipe and fuel tank	Is there any fault in pressure/vacuum line?	Repair or replace the hoses and pipes.	Replace the fuel tank pressure sensor. < Refer to FUEL TANK PRESSURE SENSOR . >