You can’t put the role of the purge valve in only a few words. It regulates the flow of fuel vapors to the engine, ensures well-performed combustion, and drops harmful vapors. But what if it turns worn or damaged? Perhaps, a proper purge valve replacement is a must once you face rough idling, low fuel efficiency, and even engine misfires.

And DriveRevolve is here to help with top-tier recommendations with the ins and outs for all. What’s more, learn about their pros and cons before purchasing. 

What Are The Sure Signs Of A Faulty Purge Valve? 

Regarding the symptoms of the malfunctioning purge valve, focus on lousy fuel economy, performance issues, check engine light, rough running, vacuum leaks, and emission inspection failure.

Drop Fuel Economy

If the purge valve does not function correctly, it can release fuel vapors necessary for your auto to burn. Consequently, the auto will need to consume more fuel to generate the same amount of power, dropping fuel efficiency. 

What Are The Sure Signs Of A Faulty Purge Valve? 
Purge valve’s outlook. Source:

Performance Issues

Once the purge valve gets stuck in an open position, you may catch sight of a vacuum leak formation. In other words, an abnormal air amount can enter the combustion chamber, disrupting the engine’s air-fuel ratio and triggering other problems.

In some cases, your auto may even shake abnormally and lose its power.

Check Engine Light

The purge valve is often the culprit behind the check engine light. When this valve malfunctions, the PCM, or Powertrain Control Module, detects the issue and triggers the check engine light. While this light can be irritating, it serves an essential purpose – impeding any potential threat to your engine.

Connect your car to an OBD2 scanner to retrieve the codes when the check engine light is on. These codes will indicate if the purge valve is indeed faulty. Once you confirm the diagnosis, replace the purge valve if needed.

Fortunately, this is a relatively simple job that doesn’t require many tools, making it ideal for novices stepping into the car’s upkeep. 

Rough Running After You Top Off With Gas

Your auto may run rich once the purge valve gets broken and stuck in the open position. At that point, excessive fumes enter the engine and disrupt the fuel-to-air mixture.

This also illuminates the check engine light. The vehicle’s computer pinpoints the improper fuel-to-air mixture and alerts you through the warning system.

What’s more, you may face rough performance and extreme instability at idle. This is particularly noticeable after refueling the tank with fresh gas, as high-concentration fumes need to escape.

With a wrong purge valve, these fumes try to get out and make their way into the engine. As a result, the fuel-to-air mixture is messed up, throwing a toll on the car’s idle.

Rough Running After You Top Off With Gas
A broken purge valve may cause other hardships. Source: Amazon

Vacuum Leaks

Driving with a faulty purge valve may end up with vacuum leaks. This is especially true if the valve is stuck in a closed position. A stuck valve can create excessive pressure, potentially leading to vacuum hose cracks, allowing gasses to escape into the atmosphere.

One noticeable symptom of a vacuum leak is a hissing sound coming from your car. If the engine is hissing while idling, the vacuum system is broken, and fumes escape into the bay.

This will worsen your emissions and result in increased automatic emissions. The gasses that should be injected into the combustion chamber escape into the atmosphere instead. That’s why driving with a faulty purge valve is quite dangerous.

Emission Inspection Fail

If you try registering a car with a faulty purge valve, you’ll face a big problem – failing the emission inspection. This means you can’t register the vehicle in your state. The government agency will inform you that you must fix the purge valve issue and return the car for another inspection.

Watch this video for a clearer picture of the dilemmas surrounding a bad purge valve.

How Much Is A Purge Valve Replacement And Repair?

How Much Is A Purge Valve Replacement And Repair?
Get it changed if needed. Source: rxmechanic

Fortunately, repairing your purge valve won’t dent your wallet. On average, the total expense for fixing a faulty purge valve ranges from $100 to $200. Most of this cost is attributed to the price of the replacement valve, which can be as high as $100.

And driving with a bad purge valve when the part is so cheap is out of the question, to be honest. You cannot delay the repair and fix the valve as soon as possible for something that cheap.

Even if you ain’t mechanically inclined, following a few online tutorials may help with a defective purge valve. Just need to locate and replace it with the new one. Make sure that you reconnect everything, and you are good to go.

How To Diagnose A Lousy Purge Valve?

To troubleshoot a check engine light, adopt an OBD-II scanner to retrieve the diagnostic trouble codes (DTCs) related to the problem. If the codes indicate an issue with the purge valve, replace it.

Furthermore, inspect the vacuum leaks, which can cause symptoms similar to a faulty purge valve. Inspect the vacuum lines and fittings for wear or damage, and alter any compromised components.

To save the purge valve’s proper function, test it using a multimeter. Measure the valve’s resistance and compare it to the manufacturer’s specs. While the resistance is outside the recommended range, change your valve.

How To Replace A Purge Valve – DIY Approach

Replacing a purge valve is a fairly easy task using simple hand tools. Here are the steps for you:

  • Seek your purge valve: this component is typically located near the fuel tank or in the engine compartment. Consult the owner’s or service manual to find it.
  • Disconnect your electrical connector: Utilize a screwdriver or pliers to disconnect your electrical connector from your valve.
  • Remove your vacuum hose: Apply pliers to detach the vacuum hose from your valve, being cautious not to ruin your fittings or hose.
  • Dismantle your purge valve: Use a socket wrench to uninstall the bolts or screws securing the valve. Take out the valve from its mounting spot.
  • Install the new purge valve: Place the new one in the same position as the old one. Use the bolts or screws to keep it in place.
  • Reconnect the vacuum and electrical connectors: Reattach the electrical connectors and vacuum hoses to your new purge valve.
  • Test the new purge valve: Start the engine and observe for indications of poor performance or rough idling. If stuff takes its right function, head for the replacement.

How Often Should I Change My Purge Valve?

How Often Should I Change My Purge Valve?
The optimal time for purge valve’s upkeep. Source: Pexels

There is no established timeline to replace purge valves. It doesn’t frequently break down, and typically it lasts the car’s entire life. Rarely, it could malfunction or sustain damage and need replacing. Consult the owner’s handbook for detailed maintenance schedules and further information regarding the EVAP system.

Asking the brand or specialist, or buff is recommended in such cases. Some auto brands also have details on their websites, comfortable for car owners to refer to if needed.


What Does A Purge Valve Do?

In the world of EVAP systems, the purge valve is the superstar. It traps your fuel vapors inside the fuel tank, impeding them from escaping into the air. It’s controlled by a solenoid, a fancy gadget knowing exactly when to close and open that valve. 

To this end, well, it gets input from a bunch of sensors. When your engine takes a break, the purge valve does, too – it stays closed. 

But when the engine gets back on its feet and reaches its ideal temps, that valve opens up to keep those sneaky fuel vapors from escaping the fuel tank. When your engine starts operating, the ECU – your car’s brain – sends pulses to the solenoid, requesting it to open the valve. 

That’s when the magic happens. Some of those fuel vapors flow into the engine, where they’re burned up and put to good use. It’s a tip-top dance between the solenoid, the purge valve, and your engine.

May A Wrong Purge Valve Create Misfire?

Yes. Driving with a faulty purge valve can lead to an unexpected consequence – misfires. Misfires due to a malfunctioning purge valve may disrupt the air-to-fuel ratio. 

This imbalance affects the combustion process, causing hassles. It’s integral to note that the fuel vapors trapped in the EVAP system contribute to a significant portion (around 5% to 10%) of the fuel burned in the engine. If the purge valve fails to open improperly, it can significantly reduce this amount, resulting in incomplete combustion and ultimately leading to misfires.


Purge valve replacement is an indispensable part of your car’s upkeep. Now, it’s time to get the best one for your car model. 

Based on your auto model, year, and brand, you can pinpoint the best deal for you. Do not hesitate to meet an expert and seasoned mechanic to resolve this issue soon. Jot something down if you want a conversation for further details!

Many more fun auto part articles are waiting for your visit. Spend your time if needed! 

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