April 5, 2026: LEMON Manuals is launched! Read the announcement.

DTC P1451: EVAP System Clog Detected (Pipe): Notes

DTC detecting condition:

Detected when two consecutive driving cycles with fault occur.

CAUTION: After servicing or replacing faulty parts, perform Clear Memory Mode Refer to ENGINE (DIAGNOSTICS) (STI)>CLEAR MEMORY MODE>OPERATION ., and inspection mode Refer to ENGINE (DIAGNOSTICS) (STI)>INSPECTION MODE>PROCEDURE .

CHECK DRAIN TUBE BETWEEN CANISTER AND LEAK CHECK VALVE ASSEMBLY.
Check the drain tube between the canister and leak check valve assembly.

Is the drain tube between canister and leak check valve assembly clogged?

Yes: Replace the drain tube between the canister and leak check valve assembly. Refer to EMISSION CONTROL (AUX. EMISSION CONTROL DEVICES) (STI)>LEAK CHECK VALVE ASSEMBLY .

No: Go to 2.
CHECK HOSE AND TUBE BETWEEN CANISTER AND FUEL TANK.
Check the hose or tube between the canister and fuel tank.

Are the hose and tube between the canister and fuel tank clogged?

Yes: Replace the hose or tube between the canister and fuel tank. Refer to EMISSION CONTROL (AUX. EMISSION CONTROL DEVICES) (STI)>CANISTER . Refer to FUEL INJECTION (FUEL SYSTEMS) (STI)>FUEL TANK .

No: Replace the canister. Refer to EMISSION CONTROL (AUX. EMISSION CONTROL DEVICES) (STI)>CANISTER .

After the operation is complete, go to the next step. Go to 3.
CHECK EVAPORATIVE EMISSION CONTROL SYSTEM.
Perform drive cycle I. Refer to ENGINE (DIAGNOSTICS) (STI)>DRIVE CYCLE>PROCEDURE>DRIVE CYCLE I .

Is DTC P1451 displayed on the display?

Yes: Replace the leak check valve assembly. Refer to EMISSION CONTROL (AUX. EMISSION CONTROL DEVICES) (STI)>LEAK CHECK VALVE ASSEMBLY .

No: End.