P1456 HONDA - Evaporative Emissions Control System Leakage Fuel Tank
Tech notesUsually, loose or bad fuel tank filler cap will trigger this codes. Retighten fuel tank filler cap and erase code to repair the problem.
There is a Honda factory service bulletin with information on how to diagnose the P1456 on the following Honda models:
1998 Honda Accord
1999 Honda Accord
2000 Honda Accord
1998-2000 Honda Accord Factory Service Bulletin OBDII Code p1456
Troubleshooting DTC P1456 (EVAP system leakage [fuel tank system]) in a 2003-2004 Pilot? Pinch off all the hoses between the fuel filler neck and the fuel tank, and retest. If the leak stops, replace the fuel fill cap first. If youve still got the leak after replacing the fuel fill cap, then replace the fuel filler pipe. Theres an O-ring between the plastic and threaded part of the filler neck that may be leaking.
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When is the code detected?The P1456 code is detected when the EVAP system has a very small leak.
P1456 Honda DescriptionThe evaporative emission (EVAP) control system stores fuel vapor from the fuel tank in the EVAP canister temporarily to prevent it from escaping to the atmosphere and to enable it to be drawn into the engine by intake manifold vacuum and burned. In addition, the onboard refueling vapor recovery system (ORVR) stores fuel vapor generated when refueling in the EVAP canister.
The EVAP control system leak detection method improves the accuracy and frequency of the detection by determining faulty components and vapor leakage for each part. The EVAP control system (from the purge valve to the fuel tank) is divided into two parts. One is the "EVAP Canister Side" (from the EVAP two way valve to the purge valve) and the other is the "Tank Side" (from the EVAP two way valve to the fuel tank). There is 0.04 inch leak detection and 0.02 inch leak detection. If the 0.04 inch leak detection results are OK, the 0.02 inch leak detection runs.