P0442 — Evaporative Emission Control System Leak Detected (small leak)
Category: Powertrain Severity: Low
Updated:
DTC code P0442 means: Evaporative Emission Control System Leak Detected (small leak). It falls under the "Powertrain" category, with an estimated severity of Low. Common causes include loose or faulty fuel cap, small EVAP leak and faulty purge/vent valve; it's worth confirming the diagnosis before replacing parts.
Possible causes
- Loose or faulty fuel cap
- Small EVAP leak
- Faulty purge/vent valve
Symptoms
- Check engine light
- Fuel smell
- No driving symptoms
How to diagnose it step by step
- Remove and re-tighten the fuel cap; check its seal.
- Clear the code and drive for a few days.
- If it returns, smoke-test the EVAP system.
- Check the purge and vent valves.
- Inspect the canister hoses (they crack with age).
How to fix it
Check the fuel cap and the EVAP system hoses and valves.
Estimated repair cost
Fuel cap: $10–40. Purge or vent valve: $40–200. Smoke test: $50–150.
Frequently asked questions
What does DTC code P0442 mean?
Evaporative Emission Control System Leak Detected (small leak).
Is code P0442 serious?
Severity Low. Usually a minor fault; check the causes listed.
Can I keep driving with code P0442?
Yes, no risk to the engine; it only affects evaporative emissions.
Related codes
P0441 P0443 P0440 P0446 P0447 P0449 P0452 P0431 P0453 P0430
Refine by car make
- Audi P0442: Fuel cap or small EVAP leak.
- BMW P0442: Fuel cap or EVAP vent valve.
- Citroën P0442: Fuel cap or canister.
- Dacia P0442: Fuel cap or canister.
- Fiat P0442: Fuel cap or purge valve.
- Ford P0442: Loose fuel cap or purge valve.
- Honda P0442: Fuel cap or purge valve.
- Hyundai P0442: Fuel cap or small EVAP leak.
- Kia P0442: Fuel cap or small EVAP leak.
- Mazda P0442: Fuel cap or small EVAP leak.
- Mercedes-Benz P0442: Fuel cap or purge valve.
- Nissan P0442: Fuel cap or purge valve.
- Opel P0442: Fuel cap or vent valve.
- Peugeot P0442: Fuel cap or canister.
- Renault P0442: Fuel cap or purge valve.
- Seat P0442: Same as VW: fuel cap or EVAP leak.
- Škoda P0442: Same as VW: fuel cap or EVAP leak.
- Toyota P0442: Fuel cap or small EVAP leak.
- Volkswagen P0442: Fuel cap or small leak in an EVAP hose.
- Volvo P0442: Fuel cap or purge valve.
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