P0497 Code Meaning, Symptoms, Causes, and How To Fix It

The evaporative emission control system or EVAP system is a crucial part of the car. It helps to stop the emission of the fuel vapors in the atmosphere. It does this job by sealing the fuel tank and fuel system. The powertrain control module (PCM) of a vehicle constantly monitors the performance of the EVAP system. It triggers the P0497 engine code when it monitors a low purge flow in the EVAP system. This article explains the P0497 code meaning, causes, symptoms, and how to fix it.

P0497 Code Definition

P0497 Code – Evaporative Emission System Low Purge Flow

What Does the P0497 Code Mean?

The P0497 code represents that your vehicle’s powertrain control module (PCM) monitors a low purge flow condition in the evaporative emissions control system (EVAP) system.

The EVAP system is most commonly used in modern vehicles. When your vehicle’s engine starts operating and uses fuel, a special EVAP control system has a canister to collect extra fuel vapors that come from the fuel tank. This EVAP system gathers these fuel vapors in a charcoal canister (a closed container) until the engine is ready to make use of them.

There is a series of metal tubes and rubber hoses that are used to transfer the fuel vapors emitted from the fuel tank to the canister.

Once the PCM (Powertrain Control Module) determines that your engine is ready to use the collected fuel vapors by the EVAP system, it activates a part called the purge control solenoid.

The purge valve helps to transfer collected fuel vapors from the EVAP system into the engine’s intake manifold, where they become part of the regular engine combustion process.

When the flow of the purge vapors from the EVAP system during the purge process becomes lower than the specified limit, the PCM triggers the P0497 engine.

Causes of the P0497 Code

The P0497 code may be triggered due to different reasons. The following are the most common causes of the P0497 code:

A clogged EVAP charcoal canister
Blocked fuel tubes
Vacuum leaks
A faulty fuel pressure sensor
Bad EVAP canister vent valve
Damaged or leaked gas cap
An issue with the purge valve
Defective canister
An issue with the PCM

Symptoms of the P0497 Code

A vehicle with diagnostic trouble code (DTC) P0496 may trigger one or more of the following symptoms:

Check engine light
Hard vehicle starting conditions
Engine stalling
Rough idle
Failed emission test
Poor fuel efficiency
Strong fuel smell

How to Diagnose the P0497 Code

To diagnose the P0497 code, follow the below-given steps:

Use a scan tool to read the recorded codes in the PCM. Save the freeze frame data, then erase the error codes from the vehicle’s memory to check if they come back.
Examine the components of the EVAP system, such as the vacuum hoses, purge valve, and charcoal canister, for signs of corrosion, wear, or damage.
Check the hoses and tubes connected to the EVAP system for blockages.
Turn on your engine and pay close attention to detect a possible vacuum leak at the purge control valve and hoses.
Check the resistance of the purge control solenoid and nearby parts by using a voltage scanner.
Inspect the fuel tank pressure sensor for damage.
Find the possible leaks in the EVAP system by using a smoke machine.
Examine the electrical wires and connections related to the EVAP system.
Examine the gas cap for a leak.
After repairs, clear the codes and conduct a test drive.

Common P0497 Code Diagnostic Mistakes

Just focusing on the P0497 code and overlooking other relevant codes
Overlooking vacuum leaks
Replace the EVAP purge valve without examining electrical wires and gas cap
Not inspecting the gap cap
Replacing the unnecessary parts
Replacing parts without testing
Not clearing the codes after repairs

How serious is the P0497 code?

The trouble code P0497 isn’t highly critical, but it may lead to an increase in the emission rate. Resolving this code involves fixing minor leaks or replacing damaged tubes. After making these repairs, it’s important to clear the code and perform a test drive.

P0497 code typically doesn’t majorly contribute to engine malfunctions, but it is recommended to address it promptly.

What repairs can fix the P0497 code?

To fix the P0497 trouble code, you need to perform one or more of the following repairs:

Replace the damaged gas cap
Clean the gas cap if needed
Clean the blocked hoses and tubes connected to the EVAP system
Replace the faulty charcoal canister
Replace or repair the damaged wires
Repair the vacuum leaks
Replace the faulty fuel pressure sensor
Replace the faulty canister purge valve
Update the PCM software

Repair Costs for P0497 Code

The repair cost of the P0497 code depends on the cost of the relevant faulty part and labor cost. The estimated repair cost for the P0497 code is given below according to the relevant part:

Part	Cost
Purge Volume Control Valve replacement	$140 to $230
EVAP Vent Control Valve replacement	$150 to $220
EVAP Line repair	$20 to $120
Gas Cap replacement	$20 to $80

How to Prevent the P0497 Code?

The following control measures may help you to prevent the P0497 code:

Ensure proper tightening of your gas cap after refueling
Ensure regular maintenance
Avoid overfilling the fuel tank
Always use good quality fuel
Maintain the EVAP system
Address minor issues promptly
Keep your fuel tank full
Don’t use aftermarket fuel additives
Get regular tune-ups and oil changes

FAQ Section

What is a purge flow?

The purge flow represents the amount of fuel vapors that enter the engine cylinder from the EVAP system.

Can I drive with the P0497 Code?

Yes, you can drive with the P0497 code, but you shouldn’t drive for a long time. Driving with this code may lead to emission test failure. Therefore, you can’t drive your vehicle with this code in cities where emission test is compulsory to pass. Driving with this code may also damage other components of the EVAP system.

Can you drive with incorrect purge flow?

Technically, you may drive with poor purge flow, but driving for a long distance is not recommended. Driving with poor purge flow may cause reduced fuel efficiency and increased emissions.

What happens if your purge valve fails?

Increased emissions
Check engine light illumination
Poor fuel efficiency
Engine performance issues
Failed emissions test

How long does a purge valve last?

While the purge valve is engineered to endure for the vehicle’s entire lifespan, this is not always the case. The longevity of the purge valve predominantly relies on upkeep and regular examination. As a general estimate, purge valves typically remain functional for approximately 60,000 to 100,000 miles.

How can I fix low purge flow?

Clean the gas cap if needed
Replace the leaked gas cap
Clean the blocked hoses connected to the EVAP system
Replace or repair the damaged electrical wires
Fix the vacuum leaks
Replace the bad charcoal canister
Replace the faulty canister purge valve
Replace the bad fuel pressure sensor
Update the PCM software

Can a bad gas cap cause P0497 code?

Yes, a bad or leaked gas cap is one of the major causes of the P0497 code.