Q: Evap large leak code

asked by on

My car is not passing emission test due to code P0455 on my car. I have changed my gas cap since that's what everybody is telling me to do first. After I changed the gas cap, I have deleted my code to check if it will come up again and it did. I have NO engine check light on my speedometer. Now I'm not sure if to change my purge valve solenoid or vent valve solenoid or my charcoal canister. Please I need an advise/solution.

My car has 161000 miles.
My car has an automatic transmission.

If you have a large emission system leak the best way to find the leak is to do a smoke test and put smoke pressure in the fuel tank and it will show the smoke out of the system leak. The most common leak besides the fuel cap is the purge or vent valves. This test will pinpoint the valve that is leaking so it can be replaced. If you have no smoke machine then use a vacuum pump to check the purge valve to see if it holds vacuum? If it does not hold vacuum then replace valve.

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
  1. Home
  2. Questions
  3. Evap large leak code

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: Timing belt with water pump replacement? How much it is going to cost?

Billing question sent to CS for the replacement of the Timing Belt and the Water Pump.

Q: How do I turn on the center display?

To turn on the center display, press and hold the Brightness Control button for at least two seconds. Turn off the display by performing the same action.

Q: Can't find location of my canister purge valve

Hey there, thanks for writing in. The canister purge valve is located underneath the throttle body near the front of the motor. If you are unsure how to proceed with the code, a certified pro from YourMechanic can come to...

Related articles

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...
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...