Auxiliary Emissions ControlOBD2 Codes

P0496 – Meaning, Causes, Symptoms, & Fixes

What Does Code P0496 Mean?

  • P0496 definition: EVAP Flow During a Non-Purge Condition
  • Issue Severity: LOW – Continued driving for a short period of time is okay
  • Repair Urgency: Get this fixed within the next month to prevent catalytic converter damage.
  • Diagnosis: There may not be any noticeable driving issues with your vehicle, but your engine could be running rich which could cause catalytic converter damage. It may also be hard to start the vehicle.

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The Evaporative Emission Control (EVAP) System seals the fuel system of the vehicle in order to prevent fuel vapors from the fuel tank and fuel system from escaping into the atmosphere. This is important because fuel vapors contain a variety of hydrocarbons. Hydrocarbons form smog when they react with air and sunlight. Gasoline evaporates very quickly, so if the fuel system is open to the atmosphere a vehicle can pollute 24 hours per day without even being turned on. These uncontrolled evaporative emissions account for as much as 20% of the pollution produced by a vehicle! When trouble code P0496 is set, it means that there is an issue with the purge flow in the EVAP system. Specifically, the Evaporative system is purging fuel vapors when it shouldn’t be.

P0496 Causes

There are many potential causes of code P0496. Some are easy to check and correct yourself, such as damaged hoses or a leaky charcoal canister. Other causes are more complicated, such as a faulty EVAP purge volume control valve or poor electrical connections.

  • Faulty EVAP Purge Volume Control Valve (most common)
  • Faulty EVAP pressure sensor
  • Leaking EVAP system hose
  • Poor electrical connections
  • Leaking Charcoal Canister

P0496 Symptoms

There may not be any noticeable driving issues with your vehicle, but your engine could be running rich which could cause catalytic converter damage. It may also be hard to start the vehicle.

How Do I Fix Code P0496?

With an EVAP system fault, the first step is to get it diagnosed to figure out what is causing the problem. 

If your vehicle has this fault and you’re not comfortable diagnosing this issue at home, we recommend finding a RepairPal certified shop nearby 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 P0496?

P0496 can be caused by anything from a damaged hose to a faulty EVAP purge volume control valve. It’s impossible to give an accurate estimate without properly diagnosing the issue first. 

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 P0496 code.

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Possible Repair Costs for P0496

For error code P0496, 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.

  • EVAP Purge Volume Control Valve $150-$200
  • EVAP Line $20-$100
  • EVAP Pressure Sensor $280-$330

DIY Steps to Diagnose Code P0496

Engine code P0496 could be caused by a number of things, including old oil, the camshaft variable timing solenoid, the camshaft phaser, and more. If you’d like to try to fix code P0496 at home without throwing money at parts, you’ll want to follow the steps below for proper diagnosis. Keep in mind this is an intermediate-level diagnosis and repair and not recommended for beginners. Diagnosis beyond oil level and condition requires more specialized equipment beyond what the FIXD Sensor can provide and it can be a time and labor-intensive process for inexperienced DIYers.

DIY difficulty level: Intermediate

This repair requires mechanical knowledge and is not recommended for beginners.

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

  • FIXD
  • Digital multimeter
  • Basic hand tools
  • Vacuum gauge (optional)
  • EVAP smoke machine leak checker
  • Hand vacuum pump
  • Vehicle specific service manual

STEP 1: RESET THE CHECK ENGINE LIGHT.

Reset the Check Engine Light to see if the Check Engine Light returns in the future.

STEP 2: TEST THE PURGE VOLUME CONTROL VALVE.

If the code returns, test the Purge Volume Control Valve for a Stuck Open condition. With the key and engine off, remove the hose going to the Purge Volume Control Valve coming from the fuel tank and unplug the electrical connector to the valve. (performing this test may set another code if it does, clear the code and disregard it until after the test is completed and the vehicle is put back together). Now, start the engine and use either a vacuum gauge or your finger to see if the vacuum is coming out of the Purge Volume Control Valve where you removed the hose. If there is a vacuum, then the Purge Volume Control Valve is leaking and needs to be replaced. If there is no vacuum you could still have an intermittent failure of the Purge Volume Control Valve or another EVAP system issue. Continue the diagnosis on the next step.

STEP 3: CHECK FOR LEAKS.

Perform an EVAP system leak check. Pinch off the vent tube to the EVAP Vent Control Valve. Pressurize the EVAP system with an EVAP smoke machine leak checker. Check to see if you see any smoke leaking out from any hoses or seals. If there are any leaks, repair leaks and check to see if the concern is resolved.

STEP 4: CHECK THE WIRING.

If you find no leaks, then grab your digital multimeter and back probe the EVAP Pressure sensor signal wire. Remove the EVAP Pressure Sensor from the Charcoal Canister or disconnect the hose going to it and apply a slight amount of pressure to the sensor using the pressure hand pump. You should see the voltage change as you do this. (consult the service manual for your vehicle’s spec on what this voltage should be) If it is not in spec, replace the EVAP pressure sensor.

If the concern persists after these checks, it may be time to take the vehicle to the shop to have it diagnosed.

Common P0496 diagnosis mistakes

Replacing the EVAP Purge Volume Control Valve before checking to see if it is leaking.

Still Need Help Fixing Code P0496?

If you’ve followed the steps above and are still experiencing check engine code P0496, 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.

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35 Comments

  1. It was just my gas cap

    1. meaning what, that gas cap needed to be replaced?

      1. That warning that says “Tighten until one click, otherwise check engine light may appear” is facts, can’t have it too tight or too loose

  2. Yes it was my purge valve solenoid sensor valve $32 bucks thank God for my FIXD tool

    1. Hi James!

      That’s great to hear, I’m glad you’re happy with your FIXD sensor! Don’t forget to come back to the FIXD blog for any additional information about your Diagnostic Trouble Codes.

      The FIXD Team

    2. Hi James
      Was the purge solenoid senser valve difficult
      To repair, and where is it located
      Thanks
      Dave

      1. Easy! YouTube it. I did. Mines 25 bucks… 3 clips and top of engine towards the back on my chevy cruze

        1. Where is the canister purge valve located on a 3.6 equinox

      2. I have a 2007 Acadia but I can’t find the omission purge part on the engine

  3. Checked purge solenoid,, was not the problem. Replaced with new solenoid and nothing changed,,, Could old solenoid have issue although testing it was same as new solenoid?
    Sending car to shop to have checked.

  4. Its easy normally as the top of the engine. YouTube it. I did in my Cruze.. 3 clips. Fixing it tomo for 25 bucks!

    1. Ok once you replace the purge valve how long did it take for the check engine light to go off

    2. My gas cap needs to be sound three times to make sure it is tightened

      1. How much was a new gas cap, mine will only click once. 2010 GMC Terrain SLT V6.

  5. I replaced my solenoid valve but my check engine light is still on and my remote start doesn’t work. Any suggestions?

    1. My car does the same thing. Did you found out what it was. Thanks

      1. In most vehicles if your check engine light is on remote start will not function.

    2. I have a 2013 Cadillac with the same issue I changed the one on top of the motor that gone bad but there’s also one in the back that normally go
      es bad too close to the gas tank you can check the purge by blowing into it if air goes through that means it’s bad if it doesn’t is good

    3. Same problem, changed both,on engine and by under by gas cap line and new gas cap.I clear the check engine light and the remote start works for a week or two. 2013 Chevy Silverado LT 1500

      1. P496. P451. P456.
        The first one came up twice with pd at the end of the second one. Car would have rough start or stop giving any gas to move while driving, I think something is plugged

    4. Try clearing it with a OBD-2 scan tool and see of the light returns. Auto Zone and O`Reiily can do this for you also.

  6. My son replaced his fuel pump in his 2006 tahoe he also put in new spark plugs it was starting up but now it won’t if he let it sit for a minute it will start what could be the problem

  7. Have this code on my 03 chevy silverado 1500 5.3. I’ve replaced the purge valve/senloid, fuel pressure sensor, and the canister connected to the purge as mine was cracked. My truck is has major leaking gas from canister. I also have the code p0101 MAF sensor still on board. What is going on?

  8. I changed the Purge valve , now does the computer reset itself or do I have to plug in and reset it manually

    1. Reset it manually.

    2. Go to FIXD and press ,”Clear check engine”

  9. Hello my 2015 Chevy Cruze is misfire once or twice after i fuel up and wants to stall when idling has anyone ever had this problem?

    1. Yes my car did the same thing, it would feel like it was going to die sitting at the light. SO I recently found out it was the valve cover crank shaft I think is what its called. , its the piece on top of the engine right on top of spark plugs, there to the right is a circle that peace is what cause the car to want to stall. Found out its under warranty 10yrs or 120k miles, SO I just fixed it but today I have a new code p0469 says I need to replace purge ?? silonde sorry cant spell. Get rid of the car they suck. I have a 2015 and its at 113 k miles I commute daily good luck

  10. How can one reste the alarm after replacing the vale without a OCD II

    1. Remove the negative battery cable from your battery for a couple minutes, then reattach it. Of course, you`ll have to reset your car clock afterward.

  11. It’s not the selenoid valve on my 2012 Cruze. The vacuum leak is from the hose they attaches to the left side of it. What is that?

    1. Did you figure it out?? I have the same problem

  12. Purge valve 20 bucks on Amazon. Easy self fix. Watch this video, it’s for 2015 GMC Canyon. https://www.youtube.com/watch?v=w9Srkfoi27c But start with gas cap, tighten or replace. Give the light a few days of driving to turn off.

  13. Better yet, turn off the light with a OBD-2 scan tool, or let a parts store person turn it off for you with his, and see if the light comes back on.

  14. I replaced the purge solenoid and my check engine light has not come on since, it’s been over two weeks. I’m getting my emissions done tomorrow to verify all is good.

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