Q: Code P0456

asked by on

Evaporative Emissions System - Small leak detected. As you know this vehicle has no gas cap. I tried to clean the filler flap, clear code but it returned again.You have any ides Thanks John

My car has 42122 miles.
My car has an automatic transmission.

Hi, thanks for writing in. I’d be happy to help.

The P0456 code is for a small leak and the only way to find such a small leak is to have the system pressurized using the test port under the hood. The system is pumped full of a smoke that has a special dye in it that will show up with an ultraviolet light. Once the leak is detected then you can repair it as needed. The fuel fill valve and the purge valve under the hood is the two main areas that leak the most. This test will isolate the leaks for you and should be done before replacing any parts.

If you would like help, consider having an expert automotive technician from YourMechanic come to your home or office to inspect and diagnose this issue for you, and make any repairs as needed.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Gas leaking from underneath hose

If you have a fuel leak I would not recommend driving the vehicle until it is repaired as fuel leaks are a safety hazard. I would also recommend having your engine inspected by a professional to determine where the leak source...

Q: How do I enable/disable the power door lock switch?

The power door lock Switch allows you to lock the doors from the inside of your truck. To enable or disable the power door lock switch, make sure all of the doors are shut. From there, to enable or disable...

Q: Q: Rear wiper arm

The rear wiper arm is part of the collar that you are referring to. The arm and collar are made and molded together. Once you remove the retainer nut you can use a small puller to grab the arm and...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...