981 · Fuel

P0451

EVAP System Pressure Sensor Range/Performance

LOW SEVERITY

EVAP pressure sensor reading is implausible.

SYMPTOMS

  • Check-engine light
  • Rough idle or hesitation
  • Reduced performance
  • Worse fuel economy

LIKELY CAUSES

  • Faulty or drifting EVAP pressure sensor
  • Wiring/connector fault
  • Mechanical/intake condition skewing the reading
  • ECM/PCM fault (rare)

DIAGNOSIS STEPS

  • Compare EVAP pressure sensor live data against other sensors for plausibility
  • Inspect wiring and connector
  • Check for related mechanical causes (leaks, restriction)
  • Verify reference voltage and ground
  • Replace the sensor if out of spec

RELATED PARTS

  • EVAP pressure sensor
← All 981 codes981 hubFault finding
FLAT

Rank symptoms to causes in your garage.

Sign in for the full fault finder — ranked causes and known issues for your exact car.

Start your garage