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P0497 — EVAP Low Purge Flow

P0497 is the inverse of P0496. The ECM commands the EVAP purge valve to flow vapor from the canister into the intake during a monitor test, and detects less flow than expected — or none at all. The cause is either the purge valve stuck closed, a restricted hose between the canister and the intake, a clogged charcoal canister, or the purge valve electrical circuit failing open.

P0497 means evap low purge flow. A vehicle usually stays drivable short-term with this code, but it should be diagnosed promptly. The most common cause is failed purge valve stuck closed (mechanical or coil failure) (typically $80–$300). Causes and cost vary by make and model; confirm the root cause before replacing parts.

Severity: low powertrain Safe to drive (short term)

Reviewed by MECH AI Editorial · Last verified

What does P0497 mean?

P0497 is the inverse of P0496. The ECM commands the EVAP purge valve to flow vapor from the canister into the intake during a monitor test, and detects less flow than expected — or none at all. The cause is either the purge valve stuck closed, a restricted hose between the canister and the intake, a clogged charcoal canister, or the purge valve electrical circuit failing open.

What are the symptoms of P0497?

What causes P0497?

Cause Likelihood Estimated repair (USD)
Failed purge valve stuck closed (mechanical or coil failure) Most common $80–$300
Restricted or pinched hose between canister and purge valve Common $20–$150
Wiring open on the purge valve circuit Common $80–$350
Blocked or saturated EVAP charcoal canister Occasional $200–$600
Failed PCM driver for the purge valve circuit Rare $400–$1,500
Damaged or clogged EVAP service port creating a false low-flow reading Rare $30–$150

Repair costs are typical US ranges and vary by make, model, model year, and labor rate. A diagnostic trouble code is a symptom, not a guaranteed failed part — confirm the root cause before replacing anything.

Is it safe to drive with P0497?

In most cases a vehicle stays drivable for short trips with P0497 active, but you should diagnose and repair it promptly. This is a low-severity code — ignoring it can lead to further damage or a failed emissions test. Exact tolerance depends on your specific make and model.

How to diagnose P0497

  1. Bench-test the purge valve

    Remove the purge valve and apply 12 V. The valve should click audibly open. With voltage applied, blow air through the valve — air should pass freely. Without voltage, the valve should seal. A valve that does not open when commanded is the textbook P0497 cause.

    Tools: 12 V test source, Hand vacuum / pressure pump

  2. Verify the purge valve receives voltage during commanded operation

    Use a bidirectional scan tool to command the purge valve open while back-probing the connector. Battery voltage should appear on the power wire when commanded. No voltage = open circuit, blown fuse, or PCM driver fault.

    Tools: Bidirectional scan tool, Multimeter, Back-probe pins

  3. Inspect the purge line for kinks or blockage

    Trace the rubber line from the canister to the purge valve to the intake. Look for pinched sections (especially where the line passes under brackets), collapsed inner walls (common on aged rubber), or visible damage. A blocked line sets P0497 even with a perfect valve.

    Tools: Flashlight, Inspection mirror

  4. Test the charcoal canister

    Disconnect the purge-side hose from the canister and try to pull vacuum on it with a hand pump. A healthy canister allows some airflow; a saturated canister blocks airflow entirely. If the canister won't pass air, replace it.

    Tools: Hand vacuum pump

  5. Read mode 6 EVAP test results

    Mode 6 shows the measured purge flow during the most recent monitor run. Zero or very low flow confirms the diagnosis. A threshold-failure (just below acceptable) with a working valve points more at canister or hose restriction.

    Tools: Scan tool with mode 6 support

How do I fix P0497?

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P0497: frequently asked questions

What does diagnostic trouble code P0497 mean?

P0497 is the inverse of P0496. The ECM commands the EVAP purge valve to flow vapor from the canister into the intake during a monitor test, and detects less flow than expected — or none at all. The cause is either the purge valve stuck closed, a restricted hose between the canister and the intake, a clogged charcoal canister, or the purge valve electrical circuit failing open.

What are the symptoms of P0497?

Check Engine Light is illuminated. Vehicle will fail emissions / smog testing. Rarely any drivability symptom. Possible faint fuel smell from a saturated canister. Difficulty fueling at the pump (gas pump clicks off repeatedly)

What causes P0497?

Failed purge valve stuck closed (mechanical or coil failure) (most-common). Restricted or pinched hose between canister and purge valve (common). Wiring open on the purge valve circuit (common). Blocked or saturated EVAP charcoal canister (occasional). Failed PCM driver for the purge valve circuit (rare). Damaged or clogged EVAP service port creating a false low-flow reading (rare)

Is it safe to drive with P0497?

In most cases a vehicle stays drivable for short trips with P0497 active, but it should be diagnosed and repaired promptly — this is a low-severity code. Ignoring it can lead to further damage or a failed emissions test. Specific tolerance varies by make and model.