All codes › P0442
P0442: Evaporative Emission System Leak Detected (Small Leak)
What it means
The EVAP self-test found a small fuel vapor leak (roughly 0.040" size).
Severity: Low Small vapor leak; fuel smell possible.
Common causes
- Gas cap seal worn
- Small cracked EVAP hose
- Leaking purge or vent valve
- Filler neck corrosion
Most common causes first. Exact causes vary by make, model and engine.
Can I fix it myself?
Sometimes DIY. Replace the gas cap first; small leaks often need a shop smoke test.
Repair cost
SEEDED ESTIMATE Roughly $80–$430
Most likely repair: evap purge/vent valve. Diagnosis fees, taxes and other causes are not included.
| Line | Low | High | Basis |
|---|---|---|---|
| EVAP purge/vent valve | $34 | $190 | Typical listed retail range, source |
| Labor 0.5–1.5 hr | $50 | $240 | $100–$160/hr, shop survey |
⚠️ This is an editorial placeholder range for this type of repair. It is not based on real invoices or licensed pricing data yet. Real ranges will appear here once enough reader invoices for P0442 are verified.
Verified reader invoices for P0442: 0. Share your repair bill to help build real costs.
Tools that can read P0442
- ScanFixAI: Pro $29.99/mo or $249.99/yr
- OBDAI: Annual PRO bundle $299
- BlueDriver Pro Next-Gen: $119.95 list ($99.95 sale seen)
The Check Engine Weekly
One email a week: new AI diagnostic tools, real repair costs from reader invoices, and one code explained.
Newsletter launching soon.