Auxiliary Emissions ControlOBD2 Codes

P0457 – Meaning, Causes, Symptoms, & Fixes


What Does Code P0457 Mean?

  • P0457 definition: Evaporative Emission (EVAP) Control System Leak Detected
  • Issue Severity: MODERATE – Extended driving with this code may cause internal engine damage.
  • Repair Urgency: Get this code fixed as soon as possible.
  • Diagnosis: Although there are no immediate drivability issues of the trouble code P0457, this is the largest vacuum leak of the three (P0455P0456, 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.

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: P0455P0456, 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 Causes

  • Loose or damaged gas cap
  • Leaking or disconnected EVAP hose
  • Faulty purge volume control valve
  • Faulty canister vent control valve
  • Charcoal canister leak
  • Leaking fuel tank

P0457 Symptoms*

*In many cases there may be no noticeable issues with your vehicle

How Do I Fix Code P0457?

With a P0457 code, the first step is to get it properly diagnosed to figure out what is causing the malfunction related to the EVAP system. Using the live data function of the FIXD sensor and app allows you to read and analyze engine data to properly diagnose a P0457 code.

If the sensors are all reading correctly and you’re not comfortable further diagnosing this issue at home, we recommend finding a RepairPal-certified shop to pinpoint the problem and give an accurate estimate for repairs. 

These shops can not only help you figure out what’s going wrong before you waste time and money on the wrong parts, but they also offer a minimum 12-month, 12,000-mile warranty and stand behind all their estimates with guaranteed fair pricing.

> Find a RepairPal Certified Shop Near You

How Much Does It Cost to Fix Code P0457?

If you take your car to a shop for diagnosis, most shops will start with an hour of “diag time” (the time spent in labor diagnosing your specific issue). Depending on the shop’s labor rate, this typically costs somewhere between $75-$150. Many, if not most, shops will apply this diagnosis fee to any required repairs if you have them perform the repairs for you. From there, a shop will be able to give you an accurate estimate for repairs to fix your P0457 code.

Possible Repair Costs for P0457

When it comes to making repairs associated with the P0457 code, one or more of the below repairs may be needed to solve the underlying issue. For each possible repair, the estimated cost of repair includes the cost of the relevant parts and the cost of labor required to make the repair. 

  • Gas Cap $20-$60
  • Evap Purge Volume Control Valve $150-$200
  • Charcoal Canister Vent Control Valve $150-$200
  • Replacement Evap Line $50-$100
  • Charcoal Canister $200-$600

DIY Steps to Diagnose Code P0457

If you’d like to try to fix code P0457 at home without throwing money at parts, you’ll want to follow the steps below for proper diagnosis. Complete diagnosis may require some specialized equipment beyond what the FIXD Sensor can provide, but for the most part, this diagnosis and repair can be attempted by beginner DIYers. 

DIY difficulty level: Beginner

This repair can be attempted by beginner DIYers.

Tools/parts needed (our top picks from Amazon):

  • FIXD
  • Basic Hand Tools

Scan your vehicle to verify P0457 is the only code present. If other codes are present, they must be addressed first.


Check your gas cap to see if it is loose or damaged. If your gas cap is loose, tighten it and clear the code. 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 is not always noticeable. If your gas cap was not loose and you do not see any indications of failure, try replacing the gas cap anyway and clearing the codes. Gas caps are relatively inexpensive and are often the fix for codes related to the EVAP system.


Check all of the EVAP hoses to make sure they are routed properly and aren’t cracked or damaged. This includes the fuel tank and charcoal canister.


Check the purge volume control valve for proper operation. This valve is normally not powered on and when at rest, with no power source applied, does not allow air to pass through. It can get sticky, causing leaks. 

The purge volume control valve is usually under the hood near the airbox or intake manifold. To test, remove the hoses from either side of the purge volume control valve with the key and engine off. Blow through openings with no power supplied. If you can’t blow through them, they are sealing properly and are most likely not the cause of this EVAP leak.


Even with a large EVAP leak, the damage to hoses can be too small to see. If you have completed all of the previous diagnostic steps, a smoke test may be helpful for further diagnosis. 


If at this point the vehicle is still setting the same code, you may have a more serious problem with the EVAP system, and you should bring the vehicle to a certified shop to have further diagnostic work performed.  

Common P0457 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.

Still Need Help Fixing Code P0457?

If you’ve followed the steps above and are still experiencing issues with the emissions control system and code P0457, please contact the FIXD Mechanic Hotline if you’re a FIXD Premium subscriber or find a RepairPal certified shop near you to get the right repairs at a fair price.


Lifelong automotive enthusiast with a soft spot for offroading. Wrencher turned writer, but I still love to tinker on just about anything with an engine. Dream car: tie between a ‘71 Hemi ‘Cuda and a ’91 GMC Syclone. #GirlDad #SaveTheManuals

Jeffrey N. Ross
Lifelong automotive enthusiast with a soft spot for offroading. Wrencher turned writer, but I still love to tinker on just about anything with an engine. Dream car: tie between a ‘71 Hemi ‘Cuda and a '91 GMC Syclone. #GirlDad #SaveTheManuals

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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.

  13. Q1) My PO457 light comes on for a few days and goes off for a week or two and comes back on. In the Travis Wright comment listed above, he may be from England and so some of the words he is using isn’t familiar to Americans, but is he talking about smearing Lucas Oil Stop around the rubber gasket in gas cap, the thing you have to unscrew and take off before you can put the fuel nozzle into the gas tank and fill up your car?

    Q2) Can someone direct me to the instructions on how to turn the warning light off? If it means anything,I have the least expensive Fix’d they offer and don’t know if you can do it with this one.

    Q3) Can anyone guess if this is a problem they would test for when you get a renewed inspection sticker for your car? I realize the rules are probably different from state to state and I’m hoping this isn’t something they test for, but it probably is I’m guessing, and would prevent renewal, right? It is a 2002 Ford Taurus SE with 58,000miles.

    1. Hey there, I can’t help with all your questions, but I can answer #2 with this article:
      FIXD can clear the check engine light, with the exception of major issues that could cause safety concerns or catastrophic damage.

      In regards to Q3: You’re correct, this varies by state. Check with your state’s inspection requirements online for the most up to date information.

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