P0455 on the Subaru Outback: Meaning, Causes & Fix
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P0455 on the Subaru Outback
We don't yet have a sourced, Subaru Outback-specific note for P0455. The general causes below apply; ask Wrenchit AI with your year and engine for a ranking specific to your car.
Subaru Outback codes & symptoms · Subaru Outback recalls · Subaru Outback maintenance schedule
Causes ranked by likelihood
| Cause | Likelihood | DIY difficulty |
|---|---|---|
| Loose or bad gas cap — Tighten until it clicks 3 times. If light persists 50 miles, replace cap (~$15). | Most likely | 1/5 |
| Cracked EVAP hose — Inspect rubber hoses near the gas tank and engine bay. | Possible | 1/5 |
| Faulty purge or vent valve — Solenoid stuck open or closed. | Less likely | 1/5 |
| Damaged charcoal canister — Less common but possible after rear-end damage. | Less likely | 1/5 |
Symptoms of P0455
- Check engine light only
- Possible fuel smell
How to diagnose P0455
- Confirm the code. Read P0455 with an OBD-II scanner and note the freeze-frame data (speed, temperature, load) recorded when it set.
- Check for companion codes. Look for other stored or pending codes such as P0440, P0442, P0456 — they often point to one shared root cause.
- Check: Loose or bad gas cap. Tighten until it clicks 3 times. If light persists 50 miles, replace cap (~$15).
- Check: Cracked EVAP hose. Inspect rubber hoses near the gas tank and engine bay.
- Check: Faulty purge or vent valve. Solenoid stuck open or closed.
- Check: Damaged charcoal canister. Less common but possible after rear-end damage.
- Clear and verify. After the repair, clear the code and complete a full drive cycle to confirm P0455 does not return.
Can I drive with P0455?
Yes, P0455 doesn't affect drivability — but you'll fail emissions testing.
Related codes
Related symptoms
Other codes on the Subaru Outback
Frequently asked questions
What does P0455 mean on a Subaru Outback?
P0455 means evaporative emission system large leak detected. P0455 means there's a large leak in your fuel vapor (EVAP) system. The #1 cause is a loose, missing or cracked gas cap — tighten it first before spending any money.
Can I drive with code P0455 on a Subaru Outback?
Yes, P0455 doesn't affect drivability — but you'll fail emissions testing.
What is the most common cause of P0455?
Loose or bad gas cap — Tighten until it clicks 3 times. If light persists 50 miles, replace cap (~$15).
What are the symptoms of P0455?
Check engine light only, Possible fuel smell.
How much does it cost to fix P0455 on a Subaru Outback?
A typical shop repair range is $0–$500, depending on which cause it turns out to be. Cheaper causes such as damaged charcoal canister should be ruled out first.