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Severity: Low Code type: Manufacturer-specific (Chevrolet)

Chevrolet P1441 Code: EVAP System Flow During Non-Purge

Engine vacuum is reaching the fuel tank even though the PCM has the EVAP purge valve turned off.

At a glance

Severity: 2/5 – Low2/5

Severity: Low

Meaning
EVAP System Flow During Non-Purge
System
Emission Controls · Powertrain
Safe to drive?
Yes, short term
Typical repair cost
$50–$600
DIY difficulty
Moderate

P1441 is the GM code used on many Chevrolet cars and trucks from the mid-1990s into the early 2000s for what newer vehicles call P0496. To run the test, the PCM commands the canister purge valve off and closes the vent valve to seal the tank, then watches the fuel tank pressure (FTP) sensor. In a sealed tank with purge off, pressure should stay near atmospheric or rise slightly as fuel warms. If the FTP sensor instead shows vacuum building, air is being drawn out through a path that should be closed, almost always a purge valve that leaks or sticks open. A purge valve stuck open can also make the engine hard to start right after refueling, because it floods the intake with fuel vapor.

Can I keep driving? Driving is fine. If the engine stumbles or is hard to start after filling up, don't top off the tank past the first click, and get the purge valve checked soon.

How to read P1441

How to read P1441P11243414
  1. P Powertrain
  2. 1 Manufacturer-specific
  3. 4 Auxiliary emission controls
  4. 41 Specific fault

Symptoms

  • Check engine light
  • Long cranking or stumble right after a fill-up
  • Rough idle for a minute after refueling
  • Whoosh of air when the gas cap is removed after driving
  • Occasional fuel vapor smell near the engine

Possible causes

Ranked by how often each cause is behind this code (editorial estimate).

  1. Canister purge solenoid leaking or stuck open 48%
  2. Fuel tank pressure sensor reading skewed toward vacuum 16%
  3. Charcoal granules from a broken canister lodged in the purge valve seat 12%
  4. Misrouted or swapped vacuum/purge hoses after repair work 10%
  5. Canister vent path restricted so tank vacuum can't bleed off 9%
  6. Purge control circuit shorted to ground, keeping the solenoid energized 5%

Diagnosis step by step

Diagnostic flow: P14411Check FTP sensor at rest2Test the purge valve for leakage3Bench-check the valve4Look for charcoal and hose routing5Check the control circuit6Clear and complete the EVAP test

  1. Check FTP sensor at rest

    Remove the gas cap and, with the key on and engine off, read the fuel tank pressure sensor. On GM systems it should read close to 0 in H2O, typically about 1.3–1.7 V on the signal wire; a reading far from that means a sensor problem rather than real vacuum.

    Tools: OBD-II scanner, Multimeter

  2. Test the purge valve for leakage

    With the engine idling and purge commanded off (or just after start-up, before purge begins), disconnect the purge hose on the canister side of the valve and feel for suction. There should be none; any vacuum means the valve leaks.

    Tools: OBD-II scanner

  3. Bench-check the valve

    Remove the purge valve and apply vacuum to the engine side with a hand pump. With no power it should hold vacuum; with 12 V applied it should open and release it. Solenoid resistance on most GM purge valves is roughly 20–40 Ω.

    Tools: Vacuum gauge, Multimeter

  4. Look for charcoal and hose routing

    Black grit in the purge hose or valve means the canister is breaking down and will ruin a new valve; replace the canister too. Confirm the purge and vent hoses are routed as shown on the underhood emission label.

    Tools: Flashlight

  5. Check the control circuit

    With the valve unplugged and key on, the PCM control wire should not be grounded while purge is commanded off. A permanently grounded wire points to a chafed harness or a PCM driver fault.

    Tools: Multimeter

  6. Clear and complete the EVAP test

    After the repair, clear the code. The EVAP monitor needs specific conditions (cold start, tank between about a quarter and three quarters full), so it can take a few days of normal driving to show ready.

    Tools: OBD-II scanner

Where the parts are

EVAP system: gas cap, canister, purge and vent valves – P1441123456
EVAP system: gas cap, canister, purge and vent valves
  1. 1Gas cap
  2. 2Charcoal canister
  3. 3Purge valve
  4. 4Vent valve
  5. 5Fuel pump
  6. 6Intake manifold

Repair options & costs

RepairDIY?Estimated cost
Replace canister purge solenoid Yes $50–$250
Replace fuel tank pressure sensor No $90–$400
Replace EVAP canister (charcoal contamination) No $200–$600
Correct hose routing / repair purge wiring Yes $50–$200

Rough US estimates for parts and labor; shop rates vary by region. Not a quote.

Emissions / smog test impact

Will fail

A check engine light from P1441 fails US OBD emissions inspections, and the EVAP monitor has to run to completion after the repair; some states allow one incomplete monitor on older vehicles.

Frequently asked questions

Is P1441 the same as P0496?

Essentially, yes. Both describe unwanted vacuum flow into the EVAP system while purge is off. GM used P1441 on older models and moved to the generic P0496 later.

Can topping off the gas tank cause P1441?

Indirectly. Overfilling pushes liquid fuel into the charcoal canister, which can break down and send granules into the purge valve, jamming it open.

Why is my truck hard to start after filling up?

A purge valve stuck open lets fuel vapor from the tank flow straight into the intake while the engine is off or starting. The overly rich mixture makes starting difficult until it clears.

Will a new gas cap fix P1441?

Unlikely. The cap is linked to leak codes such as P0455 or P0457. P1441 is about too much vacuum, typically from the purge valve.

Sources