Q: I got a code for my EVAP (P1457)

asked by on

This code is meant for my EVAP. I recently replaced my purge valve, charcoal canister, and the solenoid and all my hoses are crackless, and also my plug that attaches to it is clean and intact. I can't seem to find the problem, there's supposably a small leak somewhere. One of myfriends, says it's my PCV valve. Is this possible? What do you think is the best possible thing to do. If it isn't that one part.

My car has 151000 miles.
My car has an automatic transmission.

First, it is not the PCV. (positive crankcase ventilation) The PCV is there to relieve pressure and gases from the crankcase. The evaporative system keeps the fuel in the fuel tank from evaporating into the atmosphere. They are two separate systems.

This particular code simply states there is a problem with the evaporative emissions system. It doesn’t really point to any one thing wrong, such as a leak. Since this code is so generic, a total system test will need to be run. This can only be done with a shop level scanner and a technician with the experience to understand the results. Evaporative system tests will activate all the valves and solenoids in the system in a fashion that will reveal what to look for. It could be a leak, a solenoid that is not working or a sensor that is reading incorrectly. There are pressure sensors on the fuel tank that are used by the system to check for leaks. This is done by using the vacuum in the engine to put the fuel tank into low pressure. If the tank does not hold this low pressure condition, a code will be set. This is a simplified version of the test. If the sensor is showing an incorrect value, the system will assume there is something wrong.

If it is a leak that needs to be chased, the most common place for leaks in an evaporative system, are the seals that seal the hose connections. When these seal dry, they contract and begin to leak. The best way to look for any leak in an evap system is through the use of a smoke machine. Unfortunately, smoke machines are expensive. It creates pressure in the evap system and injects smoke into it as well. Smoke will escape out any leak in the system.

Because of the tools involved and the complicated nature of evaporative emissions systems, I recommend the following inspection to help you out. Check engine light is on inspection

Good luck!

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. I got a code for my EVAP (P1457)

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: Car shakes and won't accelerate.

This may be due to an issue with your ignition system. A severe misfire can cause an engine to accelerate very poorly and can also cause the vehicle to shake badly. If you have a check engine light I would...

Q: System Gross Leak Evaporative Emission p0455

The code P0455 will not be fixed by having an oil change and tune up. The evaporative leak may just have been caused by a loose or leaking gas cap. The system will need to be tested by leak testing...

Q: Q: Exhaust

The first thing you should have checked is the new muffler and exhaust to see if the exhaust is hitting a body part or a heat shield. This is very common in aftermarket exhaust repairs. I would recommend going back...

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...