P0442
Low SeverityEVAP System Small Leak Detected
EVAP System
What Does P0442 Mean?
A small leak in the EVAP system, often a deteriorated gas cap seal or a tiny crack in a hose.
Common Fix
Replace gas cap
Estimated Cost (DIY)
$5 - $15
Symptoms
- ⚠️Check engine light
- ⚠️No driveability symptoms
- ⚠️Failed emissions test
Common Causes
Deteriorated gas cap seallikely
Small crack in EVAP hosepossible
Loose hose connectionpossible
Cracked charcoal canisterunlikely
How to Diagnose P0442
- 1Replace gas cap (cheapest fix)
- 2If code returns, smoke test EVAP system to find leak
- 3Inspect all EVAP hoses and connections
- 4Check canister and purge valve
Need to read or clear this code?
Shop OBD2 Scanners on Amazon →Frequently Asked Questions
- Is P0442 serious?
- Not at all — there is zero effect on driveability. It only matters for emissions testing.
- Can P0442 go away on its own?
- Sometimes — if the gas cap was not fully tightened, tightening it and driving for a few days may clear it.