Subaru Fault Code

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P0455

Gas Cap Light / Active Check Engine

System

Emissions / EVAP

Symptom

Gas Cap Light / Active Check Engine

Diagnosis & fix steps

LOGIC: Evaporative Emission System Leak Detected (Gross Leak). ACTION: Inspect the fuel filler neck for severe rust pitting around the gas cap seal. Smoke test the EVAP lines running back to the charcoal canister; inspect the canister vent valve for salt/dirt contamination.

Red Seal field insights

Filler Neck Corrosion: Road salt, mud, and water kick up into the right rear wheel arch, rusting the thin steel filler neck until pinholes form beneath the protective plastic guard.

Same code keeps coming back?

That's a program problem, not a part problem. Book a 30-minute uptime review with Grant, a Red Seal Heavy Duty Technician.

Book an uptime review

Read before you touch anything

  • This is general reference information, not a repair manual. It is for trained, qualified technicians.
  • Fault codes, meanings and procedures vary by model, serial number and software version. Confirm the code and the procedure against the manufacturer's service manual before acting.
  • Follow the OEM service manual, torque specs and your site's safety procedures: lockout/tagout, block raised equipment, relieve hydraulic, fuel and air pressure, and let hot systems cool.
  • You use this information at your own risk. Adventure Mechanical and AM Fleet Integrity accept no liability for damage, injury, downtime or loss arising from its use.
  • Not affiliated with or endorsed by any manufacturer. Brand names are used only to identify the equipment a code applies to.

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