Skip the auto shop - Our mechanics make house calls

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.

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

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?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

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: p1120 out of service code

Hi. The code P1120 is a problem with the throttle position sensor. The input from the throttle position was not what the computer expected and would cause the computer to go into a failure limp mode. When the computer is...

Q: How do I use the personal lights?

Your vehicle has two overhead personal lights, which are located on the ceiling. To turn on the lights, press the button next to each light. Press this button again to turn the lights off.

Q: Issues with MAF sensor and P010B code

The vehicle's Engine Control Module (ECM) may need reprogramming, as to a technical bulletin ITB09-028 dated June 3, 2009. The reprogramming by the dealer will be needed to try and see if the code goes away, if not, further diagnosis...

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
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 P0052 code means This code is seen when the Engine Control Module (ECM) tries to control the...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.