If you have a Nissan and it is giving a P0456 error code, the onboard computer (ECM) is seeing a problem with the EVAP system.
The official definition of a Nissan P0456 error is a “Small Leak Detected in the EVAP System.”
What is a P0456 Nissan Code?
A Nissan P0456 OBDII error code is a Small Leak Detected in the EVAP System.
The EVAP system is built into modern cars to stop gas vapors from leaking into the atmosphere.
This helps reduce emissions and gives vehicles better efficiency.
When a leak happens in the system or it has a failed component, a P0456 error code will be given.
3 Causes and Fixes Nissan P0456 Code
- Gas Cap
- Purge Valve / Vent Solenoid
- Leak In EVAP System
If a gas cap is not tightened correctly or is not sealing, it will cause a small leak.
Check the gas cap is on tight and examine the rubber seal is not broken.
Grime or other debris can also sometimes stop a gas cap from making a good seal.
Some mechanics will buy a new gas cap to rule it out as a possible cause.
If you do, buy a new gas cap, be sure it is made for your Nisan make and model, as there can be differences.
It will open when a car is running and close when a vehicle is shut off.
It can fail and cause EVAP errors such as a P0456 code.
Example Nisan Vent Solenoid on Amazon
14935-AM60B EVAP Vapor Canister Vent Valve Solenoid for Nissan Maxima Altima Murano Armada Rogue Frontier Infiniti G35 QX56 FX35 Replace 14935-AM60A Evaporative Emissions Vapor Canister Purge Valve
Hard to find leaks are often found with a smoke machine.
A smoke machine will feed smoke into the EAVP system and will come out where the leak is located, making it easy to spot.
If your Nissan engine light comes on and after an OBDII scan tool gives a P0456, it is pointing to an EVAP system problem.
Most EVAP system problems are easy to fix with either the gas cap bad or a bad vent solenoid.
Although usually an easy fix, sometimes it can be hard to locate a very small leak.
If you have a smoke machine, it will be easy to locate the leak, but often most DIY individuals do not have one.
While a smoke machine can be bought, it is often best to take your vehicle to a mechanic for hard-to-find leaks.
Have you had a Nissan with a P0456 error code? Let us know your thoughts below.