Audi P0455 Code — EVAP System Large Leak Detected
The P0455 code on your Audi indicates a large leak in the EVAP system.
What It Means
The EVAP system has lost pressure due to a significant leak.
👉 Compared to P0442:
- leak is larger
- issue is usually more serious
Common Causes
1. Missing or Damaged Gas Cap
7
Most common cause.
2. Major EVAP Hose Damage
5
Causes:
- broken hose
- disconnected line
- severe wear
3. Faulty Purge Valve
- stuck open
- unable to hold pressure
4. Damaged Charcoal Canister
- cracks
- structural damage
Symptoms
- check engine light
- fuel smell
- possible starting issues
Step-by-Step Fix
- Check gas cap
- Inspect hoses
- Test purge valve
- Scan codes
- Perform smoke test
How much does the repair cost?
Cover: $10–30
Valve: $50-150
System repair: up to $300+

