INDEPENDENT REFERENCE
P0442 — Evaporative emission system small leak detected
Generic powertrain DTC · LOW priority for follow-up (not a certified safety rating)
What the code means
The EVAP system failed a small-leak integrity test.
What you might notice
Check-engine light; typically no driving difference.
Possible causes — not a diagnosis
Loose or damaged fuel cap; split EVAP hoses; valve seals; tank filler seal.
Useful diagnostic checks
Check cap and seal; inspect hoses; conduct approved low-pressure smoke testing where appropriate.
Next steps
Repair the actual leak; avoid introducing flammable vapors or excessive test pressure.
Related OBD-II codes
These generic definitions are explanatory summaries of commonly standardized OBD-II powertrain conditions. Vehicle-specific code logic and service procedures must be verified against manufacturer documentation. EPA: On-board diagnostics.