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P0456: Evaporative Emission Control System Leak Detected (Very Small Leak)
A very small leak in the EVAP system has been detected.
Low Severity
$0 – $200
Can I Keep Driving with Code P0456?
Yes, no driving issues.
What P0456 Means
P0456 is the smallest leak threshold (about 0.020 inch). Almost always a gas cap that has not been tightened completely, or a tiny crack in a vacuum hose.
Common Causes
Diagnostic Tips
- Tighten the gas cap until it clicks three times, then drive for a few days.
- If the code returns, a $15 cap usually fixes it.
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Why does P0456 keep coming back?
Usually a worn gas cap seal that intermittently seals enough to clear but then fails again.