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.
Find a Certified Shop
We've partnered with RepairPal to recommend trustworthy shops in your area. Enter your details to see certified shops near you that offer upfront estimates, guaranteed fair pricing, and a minimum 12-month, 12,000-mile warranty.
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.
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
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.
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.
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):
- 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.