P0455 on Volkswagen: How to Diagnose & Fix
Evaporative Emission Control System Leak Detected (Gross Leak)
1 Volkswagen model · 1 documented issue · $30-$500 repair
P0455 on Volkswagen by model: symptoms, diagnosis and fix
The EVAP system on MQB-platform Golf R (MK7/MK7.5, with some MK8 cases) frequently throws evaporative-emissions leak faults. The most common culprit is the N80 purge valve failing to seal, but the leak-detection pump, carbon (charcoal) canister breakdown, and saturated canister from overfilling the tank also trigger codes. Symptoms are a check engine light with small- or large-leak codes, occasional rough idle or hesitation just after start, and sometimes a fuel smell. Often surfaces around emissions/inspection (relevant for EU periodic technical inspection).
Common Symptoms
- Check engine light (EVAP leak)
- Rough idle / hesitation after start
- Fuel smell
- Failed emissions/EVAP readiness monitor
How to Fix
Read codes and smoke-test the EVAP system. Replace the N80 purge valve (inexpensive, ~USD 20-50) as the most common fix; also inspect the gas cap seal, charcoal canister and leak-detection pump. Advise owners not to overfill the tank past the first pump click-off, which saturates and damages the canister. Clear codes and run a drive cycle to confirm the EVAP monitor passes.
What you need to diagnose it
The repair instructions explicitly call for reading stored codes. Use a scanner that can read the named code families before choosing a repair.The recommended scanner supports these code families; confirm your exact year, model and module coverage before buying.
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Read & clear engine (P) codes
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Reading and clearing the code is DIY work. Module replacement or reprogramming is not — most modules are VIN-programmed, so a new one does nothing until a shop codes it to your car. Check for an open recall or service bulletin before buying anything.
Sources for this issue (3)
P0455 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0455 mean on a Volkswagen?
P0455 stands for "Evaporative Emission Control System Leak Detected (Gross Leak)." This code means your car's evaporative emission (EVAP) system has detected a large (gross) leak, so fuel vapors that should be sealed inside the fuel and vapor system are escaping into the atmosphere. The EVAP system captures gasoline vapors from the tank and routes them to the engine to be burned instead of polluting the air, and the computer periodically pressure- or vacuum-tests this sealed system. A gross leak almost always points to something obvious and easy, like a loose, missing, or bad gas cap, rather than a deep mechanical failure. It rarely affects how the car drives, but it should be fixed to pass emissions and stop wasting fuel vapor. On Volkswagen it is documented across 1 model: Golf R.
What are the most common causes of P0455?
The most common causes of P0455 are: Loose, missing, or improperly tightened gas cap, Worn, cracked, or failed gas cap seal, Cracked or disconnected EVAP/vapor hose, Damaged or missing fuel filler neck seal, Faulty EVAP purge valve stuck open, Failed EVAP vent valve, Cracked or damaged charcoal canister. The specific cause varies by vehicle.
How much does it cost to fix P0455 on a Volkswagen?
Published repair estimates on Volkswagen range from $30 to $500 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for P0455 on a different make?
View P0455 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.