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: Got a question about one of my coils misfiring

Ignition coils are coated with a varnish-like insulation that becomes brittle over time after being stretched then contracted repeatedly. The insulation develops small fractures that open when heated and close when cooled. When open, they allow shorting of coil windings...

Q: Having starting issues on my 2012 Chevy Malibu 2LT.

Hello. Your particular make and model does not have a serviceable fuel filter. The fuel filter it has is on to the bottom of the fuel pump, known as the fuel strainer. To replace the fuel filter the fuel pump...

Q: If you are replacing the heater core on your 2002 Jeep Liberty, would you also replace your thermostat at the same time?

Hi there: Anytime you replace cooling system components; like a heater core, it's always a good idea to replace the thermostat at the same time. In most cases, the thermostat is one part that tends to wear out sooner than...

Related articles

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...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...