OBD-II code · Powertrain (generic)
P0451 Evaporative Emission System Pressure Sensor Range/Performance
The fuel tank pressure sensor reading is implausible — for example, fluctuating signal, noise, or values that do not respond to known pressure events such as a key-on tank refill.
Is it safe to drive with P0451?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyTank pressure sensor drifted/noisy
- Less likelySensor element aged beyond calibration window
- Less likelySensor mounting loose - signal damping
Symptoms
- Check engine light on
- Possible smell of fuel near tank or engine bay
- Failed emissions inspection
- Loose-cap warning may appear
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.5–2.5 h
- Emissions test
- Likely to fail
- After the fix
- A drive cycle is needed before the light stays off
- Parts involved
- Fuel Tank Pressure Sensor, Sensor Wiring
Related codes
- P044EEGR Sensor C Circuit Intermittent/Erratic
- P044FSecondary Air Injection System Switching Valve A Circuit High
- P0450EVAP System Pressure Sensor/Switch A Circuit
- P0452Evaporative Emission System Pressure Sensor Low Input
- P0453Evaporative Emission System Pressure Sensor High Input
- P0454EVAP System Pressure Sensor/Switch A Circuit Intermittent
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.