P0496 EVAP purge flow when purge should be off

EVAP high purge flow (purge valve stuck open)

Monitor

EVAP faults let fuel vapour escape but rarely change how the car drives, and the main risk is a failed emissions test, so it is safe to drive while you arrange a fix.

It gets more serious if:

  • Inspect soon: You keep smelling raw fuel around the car, not just right after filling up
  • Stop: You see liquid fuel dripping or pooling under the car, or near the filler, tank or canister
  • Inspect soon: The engine stalls, loses power, or the fuel gauge behaves erratically

Source: how we rate severity

P0496 in short

P0496 means fuel vapour is being pulled into the engine when the purge valve should be closed. The usual cause is a purge valve stuck open. It is usually safe to drive, but get it checked soon if the engine stalls or the fuel gauge acts strangely, and check for open recalls.

The purge valve should stay shut until the computer opens it. When the computer closes the valve but still sees engine vacuum in the EVAP system, it sets P0496. Land Rover describes this check as looking for a stuck-open purge valve or a leak between the tank and the valve.

A valve stuck open can let engine vacuum pull hard on the fuel tank. In Ford recall 18V-735, a stuck purge valve could deform the plastic tank, giving an erratic fuel gauge, rough running or a stall.

P0441 covers the opposite fault, too little flow when the valve should be open.

Most likely causes

  1. Purge valve stuck open

    Common general cause
    Why it ranks here
    This is exactly what the monitor checks for, and it is the fault in the Ford recall and in Land Rover and GM bulletins.
    What would change this
    Rises if vacuum is present on the canister side with the valve commanded closed.
    How to test the evap canister purge valve

  2. Damaged purge valve O-ring or seal

    Supported by vehicle data
    Why it ranks here
    GM has a bulletin for P0496 from purge solenoid O-ring damage on the Encore GX and Trailblazer 1.3L.
    What would change this
    Rises if the O-rings are cut or distorted when the valve is removed.
    How to test the evap canister purge valve

  3. Charcoal debris holding the valve open

    Possible — needs testing
    Why it ranks here
    A saturated canister can shed charcoal that damages valves or holds them open.
    What would change this
    Rises if charcoal grains are found in the purge hose or valve.
    How to test the evap charcoal canister

  4. Leak between the fuel tank and the purge valve

    Possible — needs testing
    Why it ranks here
    Land Rover notes the monitor also reacts to a leak between the tank and the purge valve.
    What would change this
    Rises if a smoke test finds a leak on that section.
    How to test the vacuum hoses and intake leaks

  5. Engine computer calibration (specific Land Rover models)

    Supported by vehicle data
    Why it ranks here
    Land Rover fixes P0496 on some 2020 models with a software update.
    What would change this
    Only applies to vehicles covered by SSM 74799.

What to test first

Start at step 1. Each result tells you what it means and where to go next.

  1. Check your VIN for open recalls on the NHTSA website or with a dealer.

    Low risk

    • IfAn open purge valve recall applies (for example Ford 18V-735 on the Focus)

      It meansGet the recall done. It covers the purge valve and any damage it caused.

      Points to: Purge valve stuck open

    • IfNo open recall

      It meansCheck the hoses.

      Go to step 2

  2. With the engine off and cool, check the purge and canister hoses for splits or loose ends.

    Use cautionTool: flashlight

    Warning:Let the engine cool first. Parts in the engine bay can be hot enough to burn, and fuel vapour is flammable, so keep sparks and flames away.

  3. With the engine idling and the purge valve commanded off, check for vacuum on the canister side of the valve.

    Best left to a shopTool: scan tool with output controls, vacuum gauge

    Warning:Engine running: keep hands, hair and loose clothing away from belts and the fan.

  4. Have a shop remove the purge valve and inspect it, its O-rings and the hoses.

    Best left to a shop

    Warning:Shop work on the fuel vapour system.

Symptoms

  • Check engine light on, usually with no change in how the car drives
  • Rough idle or stalling, especially right after refuelling
  • Fuel gauge reading erratically Gets more serious: stop and have it checked.
  • Fails an emissions or smog test because of the light or an incomplete EVAP monitor
  • Persistent raw fuel smell around the car Gets more serious: stop and have it checked.
  • Liquid fuel dripping under the car Gets more serious: stop and have it checked.

Compare with: Rough idle with the check engine light on, Check engine light came on after getting gas

How to fix

  1. Check your VIN for open recalls before paying for a repair.

  2. If you have a Focus covered by recall 18V-735 that is not yet repaired, Ford advises keeping at least half a tank of fuel until it is fixed.

  3. Check the purge hoses in the engine bay are attached and not split.

    Warning:Engine off and cool.

  4. After a repair, drive normally for several days so the monitor can re-run. Clearing codes or disconnecting the battery resets readiness, so do it shortly before an inspection only if you then complete a drive cycle.

Parts and cost context

  • EVAP canister purge valve:Usually in the engine bay, on a hose between the canister line and the intake. Labour varies, so get a quote.
  • EVAP charcoal canister:If charcoal has reached the purge valve, the canister may need replacing too, or the new valve can fail again.

Labor varies by vehicle and shop; get a quote before you approve a repair.

Compare used part prices on PartPriceGuide

On your vehicle

Ford

  • 2012–2018 · Focus · 2.0L GDI, 2.0L GTDI

    Supported by vehicle data

    Recall 18V-735 covers a purge valve that can stick open without the old software noticing, so engine vacuum can deform the fuel tank. Symptoms are a check engine light, erratic fuel gauge, loss of power or a stall. The recall report does not list specific trouble codes, so this link to P0496 is based on the stuck-open purge valve it describes.

    Related recall campaigns: 18V-735

Buick

  • 2020–2025 · Encore GX · 1.3L L3T

    Supported by vehicle data

    GM PIP6037A links P0496 to possible purge solenoid O-ring damage. Check the purge hoses, then replace the solenoid and inlet duct. The bulletin is on NHTSA, but whether it is still current is not verified, so it is labelled vehicle data rather than confirmed.

  • PIP6037AStatus unverified

    P0496 and possible purge solenoid O-ring damage

    2020–2025encore-gx · 1.3L L3T · issued · NHTSA MC-11013453

    Check the purge hoses, then replace the purge solenoid together with the inlet duct. The bulletin also covers the 2021–2025 Chevrolet Trailblazer with the 1.3L L3T.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

Chevrolet

  • 2021–2025 · Trailblazer · 1.3L L3T

    Supported by vehicle data

    Covered by the same GM purge solenoid O-ring bulletin (PIP6037A) as the Encore GX. The bulletin is on NHTSA, but whether it is still current is not verified, so it is labelled vehicle data rather than confirmed.

  • PIP6037AStatus unverified

    P0496 and possible purge solenoid O-ring damage

    2020–2025encore-gx · 1.3L L3T · issued · NHTSA MC-11013453

    Check the purge hoses, then replace the purge solenoid together with the inlet duct. The bulletin also covers the 2021–2025 Chevrolet Trailblazer with the 1.3L L3T.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

Volkswagen

  • 2009–2017

    Supported by vehicle data

    VW bulletin 20 17 02 lists P0496 among the codes where the N80 purge valve may be involved on 2009–2017 gasoline models (except Routan). It says to smoke test and check vacuum before replacing the valve. The bulletin is on NHTSA, but whether it is still current is not verified, so it is labelled vehicle data rather than confirmed.

    Where it is:N80 purge valve, engine bay

  • 20 17 02Status unverified

    EVAP purge valve (N80) diagnosis

    2009–2017 · issued · NHTSA MC-10125657

    For 2009–2017 gasoline Volkswagens (except Routan), lists the EVAP codes that can involve the N80 purge valve and says to smoke test the system and check vacuum before replacing the valve.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

Land Rover

  • 2020 · AJ126

    Supported by vehicle data

    Land Rover SSM 74799 covers P0496 on the 2020 model year Range Rover, Range Rover Sport and Discovery with the AJ126 engine. The fix is an engine computer calibration. The bulletin is on NHTSA, but whether it is still current is not verified, so it is labelled vehicle data rather than confirmed.

  • SSM 74799Status unverified

    P0496 logged

    2020range-rover, range-rover-sport, discovery · AJ126 · issued · NHTSA MC-10174496

    On 2020 model year vehicles with the AJ126 engine, P0496 can be logged and the fix is a PCM calibration update. The message explains that the monitor looks for a stuck-open purge valve or a leak between the tank and purge valve.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • P0441EVAP purge flow incorrect

    Same system Common general cause

    Same valve, opposite fault. P0496 is flow when the valve should be shut; P0441 is usually too little flow.

  • P0443EVAP purge valve circuit fault

    Shares causes Supported by vehicle data

    VW lists P0496 and the purge circuit code P0443 among the codes where the same N80 purge valve may be at fault.

All EVAP (evaporative emissions) codes

P0496 questions

Can P0496 damage my fuel tank?

On some vehicles, yes. In Ford recall 18V-735, a purge valve stuck open let engine vacuum deform the plastic fuel tank, causing an erratic fuel gauge and possible stalling.

Is there a recall for P0496?

Check your VIN on the NHTSA recall site. The Ford Focus recall 18V-735 covers a sticking purge valve, and some makers have service bulletins or software updates for P0496.

Is it safe to keep driving?

Usually yes, as long as there is no strong fuel smell and no fuel dripping. Most makers advise getting it fixed when it is convenient. A strong fuel smell means get it checked soon, and dripping fuel means stop and do not drive.

Sources and review

  1. Frequently Asked Questions on On-Board Diagnostics (EPA 420-F-97-003) — US EPA ,
  2. On-Board Diagnostic II (OBD II) Systems Fact Sheet — California Air Resources Board ,
  3. EVAP: The Phantom Emissions Menace (Nissan TechNews, May 2018) — Nissan North America (hosted by AutomotiveTechInfo) ,
  4. OBD Test Reference (rev 8.6) — California Bureau of Automotive Repair ,
  5. What do you mean my car is not ready? — New York State DMV
  6. Recall acknowledgement 17V-088: BMW i3 REx fuel tank vent line may chafe — BMW of North America / NHTSA
  7. Part 573 Safety Recall Report 15V-621 (Mazda 8615J): liquid fuel can enter the EVAP canister — Mazda North American Operations / NHTSA
  8. Part 573 Safety Recall Report 18V-735 (Ford 18S32): canister purge valve may malfunction — Ford Motor Company / NHTSA ,
  9. Ford media release for recall 18V-735 — Ford Motor Company / NHTSA ,
  10. Land Rover SSM 74799: P0496 logged — Jaguar Land Rover North America / NHTSA ,
  11. GM PIP6037A: P0496 and possible purge solenoid O-ring damage — General Motors / NHTSA ,
  12. VW 20 17 02: EVAP purge valve (N80) diagnosis — Volkswagen of America / NHTSA ,
Last reviewed
Written by
Saurabh K.
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