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EmissionsSeverity Low: usually safe to drive

P0451Evaporative Emission System Pressure Sensor/Switch "A" Range/Performance

What it means

The fuel tank pressure sensor reading is implausible.

Symptoms

  • Check engine light
  • Possibly a fuel smell
  • Usually no change in how the car drives

Common causes

  • Faulty tank pressure sensor
  • Blocked vent
  • Wiring fault

What to check first

  1. Remove the fuel cap: the sensor should read about zero
  2. Compare with a gauge
  3. Check the sensor reference and ground
Can I drive with P0451? Usually yes. P0451 rarely affects how the car drives, but it keeps the check engine light on and can fail an emissions test.

Generic OBD-II meaning. Manufacturer-specific meanings and checks can differ; always check the service information for the car.

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P0451: questions and answers

What does P0451 mean?

P0451: Evaporative Emission System Pressure Sensor/Switch "A" Range/Performance. The fuel tank pressure sensor reading is implausible.

What are the symptoms of P0451?

Check engine light. Possibly a fuel smell. Usually no change in how the car drives.

What causes P0451?

Faulty tank pressure sensor. Blocked vent. Wiring fault.

How do you diagnose P0451?

1. Remove the fuel cap: the sensor should read about zero 2. Compare with a gauge 3. Check the sensor reference and ground

Can I drive with P0451?

Usually yes. P0451 rarely affects how the car drives, but it keeps the check engine light on and can fail an emissions test.