P0455 on Subaru: Symptoms, Causes & DIY Fix
Official technical diagnostic wire for fault code P0455 (P0455: Evaporative Emission Control System Leak Detected (Gross Leak)) specifically affecting Subaru vehicles (Outback, Forester, Crosstrek, WRX, Ascent).
1. Symptoms of P0455 on Subaru
When the Engine Control Module (ECM/PCM) on your Subaru logs fault code P0455, drivers commonly observe:
2. Most Likely Causes on Subaru
Historical warranty claims and technical repair bulletins for Subaru point to the following failure distribution:
3. Step-by-Step DIY Repair Guide for Subaru
Remove gas cap, inspect rubber O-ring for cracks, tighten until it clicks 3 times. on Subaru vehicles (Outback, Forester).
If the cap rubber is dried or cracked, replace with genuine OEM cap ($15). on Subaru vehicles (Outback, Forester).
Disconnect electrical plug and vacuum hose. Apply 12V; verify valve seals tight when unpowered. on Subaru vehicles (Outback, Forester).
Check vent valve for road salt corrosion or spider nest clogs. on Subaru vehicles (Outback, Forester).
Pump mineral oil smoke into EVAP port to reveal any hairline cracked lines. on Subaru vehicles (Outback, Forester).
4. Subaru P0455 FAQs
What causes code P0455 to trigger on a Subaru?
On Subaru vehicles, P0455 is most frequently caused by Missing, loose, or cracked gas cap seal or Faulty EVAP purge control solenoid. Factory sensor degradation or wiring harness wear near the engine bay are common factors.
Can I safely drive my Subaru with code P0455?
Yes. Completely safe to drive, but emissions test will fail. Given that P0455 carries a Low severity rating on Subaru vehicles, we advise performing diagnostic scanning via the OBD-II port before extended driving.
How much does it cost to fix P0455 on a Subaru?
DIY replacement parts typically range between $15 - $250 (DIY: $15 - $50). If serviced at an authorized Subaru dealership, expect an additional $120–$250 in professional labor based on their $115/hr hourly rate.