Auxiliary Emissions ControlOBD2 Codes

P0457 – Meaning, Causes, Symptoms, & Fixes

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Code P0457 Definition

Evaporative Emission (EVAP) Control System Leak Detected

What Does P0457 Mean?

The Evaporative Emission (EVAP) Control System is in vehicles to prevent the emissions of fuel vapor (hydrocarbons) into the atmosphere. The EVAP system communicates with the PCM and when there is a vacuum leak in the system, there are one of three codes that can be triggered: P0455, P0456, or P0457 depending on the severity of the leak. When the trouble code P0457 is set, there is a large leak in the EVAP system.

P0457 Symptoms

P0457 Causes

  • Loose or damaged gas cap
  • Faulty or stuck vent control valve
  • Faulty or stuck purge valve
  • Cracked or disconnected EVAP hose
  • Cracked or damaged charcoal canister

Code P0457 Severity – Moderate


Although there are no immediate drivability issues of the trouble code P0457, this is the largest vacuum leak of the three (P0455, P0456, P0457). It depends on where the issue is coming from in the EVAP system but this could lead to larger leaks and more issues in the future.

Code P0457 Common Diagnosis Mistakes

Many people fail to follow the full diagnostic test and can underpay or even overpay for their solution. Fuel caps ($) are the easy fix with a run to your local auto repair shop, but people sometimes neglect the possibility of  other components it might possibly be which are more costly ($$).

P0457 Diagnosis

Difficulty of Diagnosis and Repair – (1-4)

  1. Scan your vehicle to verify P0457 is the only code present. If other codes are present, they must be addressed first.
    1. If you have code P0440, P0455, or P0456, the cause of the codes is most likely a solenoid failure, or a more complex system leak. These issues must be addressed first.
  2. Check your gas cap to check if it is loose or damaged
    1. If your gas cap is loose, tighten it and clear the code.
    2. Inspect your gas cap for physical damage or deterioration. However, it should be noted that damage to the gas cap or deterioration of its components are not always noticeable. If your gas cap was not loose and you do not see any indications of failure, try replacing the gas cap anyways and clearing the codes. Gas caps are relatively inexpensive and are usually the fix for code P0455.
  3. Check for cracked or disconnected EVAP hoses near or connected to engine air box
    1. Replace cracked/disconnected hoses
    2. Clear code*
  4. If you would like to test the EVAP system yourself, check out Part 1 and Part 2 of these videos for a visual reference.


*If code returns, you will need to be given further diagnostics at a mechanic. More diagnostic steps could require electrical testing of the purge and vent control valves for proper operation. It may also require a smoke machine test to detect and find a leak in the system.[/vc_column_text][/vc_column][/vc_row][vc_row][vc_column][/vc_column][/vc_row]

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  1. I am going to check the hoses first. I need to know how to clear the check engine light off of my vechicle without disconnecting the battery.

  2. My truck light comes on for the fuel inlet. I’ll fix that 1st & hope that fixes the issue. Ty

  3. I have had the system smoke tested and replaced several parts. No leaks left but code P0457 still keeps coming back.

    1. I have the same code PO47. I’m presuming faulty gas cap something in that area. It’s not leaking gas from the cap. So must be must be some sort of Vacuum or pressure that is sending a signal to the dashboard for this code. Any ideas on how I can make this correction and fix this problem?

  4. I checked all that stuff and the codes p0457,p0456, and p0440 persists and the car still turns but doesn’t start. I’m guessing fuel relay behind front driver side bumper maybe?

  5. Your info helped me with my “Check engine “ light issue. Simple fix , replaced the gas cap. Problem solved. $12.00 fix. Thanks.

  6. I just replace my canister, purge valve and purge valve along with gas cap an i still have the famously p0457 code is there anything else i need to replace? Oh it does have a short ram intake from the previous owner could that be giving out the code?

  7. It was a separation from the catalytic converter. Thank you. This is a great service!

  8. I greased the geometry seal on gas inlet door. Added a little of Lucas Oil stop leak to the inside of the fuel nozzle and smeared it around. Light and code was clearable and no repeat light or code so far.

  9. On older F150’s (mine is a 2002) I had to replace the gas gauge sensor. When removing my bed I found a sensor (after I broke it) that was attached right on top of the gas tank. It caused the P0457 code. The Evaporative Emission (EVAP) Control System is in vehicles to prevent the emissions of fuel vapor (hydrocarbons) into the atmosphere. When I found I broke it I didn’t think it mattered until I replaced the gas gauge sensor and put everything back together. Because of its position on top the gas tank I am not sure if you can get to it with the bed on the truck. I have 339,998 miles on my truck and have chose to drive it like it is. If you are getting this code and have tried everything else, check the one on top the gas tank.

  10. Get a FIXD code reader you can clear it with that

  11. Found the purge valve supply hose loose and causing a vacuum leak up stream which created a rich downstream auction sensor and a vacuum leak. Put a clamp around vacuum line to tighten it at the purge valve. Clear the codes will run car see if codes come back.

  12. Not the gas cap for sure not one on it. Was getting check fuel inlet. blew dirt out and lubed up the valve with funnel. so far so good.

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