Evaporative Emission System Small Leak Detected
Detected a small leak in the evaporative emissions system.
Heads up: this code wasn't in our hand-written library yet, so DiagCoach AI built this page on the fly. Double-check critical specs against service info before condemning parts.
What it means (plain English)
The system that controls fuel vapor emissions from the gas tank has found a tiny leak, which can be caused by anything from a loose gas cap to a crack in the hoses.
What the computer is actually seeing
The engine control module (ECM) detects that the pressure in the EVAP system is dropping too quickly during a self-test, indicating a small leak.
What a healthy reading looks like
The system should hold pressure within a range of -0.5 to -1.5 inches of water for at least 30 seconds during testing.
Guided diagnostic — the DiagCoach way
Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.
- 11. Check the gas cap for tightness and inspect it for damage. If loose or cracked, replace it and retest.
- 22. Inspect all EVAP hoses for cracks or loose connections. If found, repair or replace as necessary and retest.
- 33. Check the EVAP purge valve operation by applying 12V directly to it; it should click. If not, replace the valve and retest.
- 44. Inspect the charcoal canister for damage or blockage. If suspect, replace it and retest.
Common causes
- Loose or damaged gas cap
- Small cracks in EVAP hoses or fittings
- Faulty EVAP purge valve
- Damaged charcoal canister
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
Yes, it's safe to drive, but fix it soon to avoid emissions issues.
Will this code come back after clearing it?
If the leak isn't fixed, the code is likely to return after a few drive cycles.
Why does this code pair with other codes?
Other codes may indicate different or related issues in the EVAP system.
Working a real vehicle right now?
Let DiagCoach walk you through it live with your specific symptoms, vehicle, and what you've already checked.
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