What does this code mean?
P0442 describes a small leak, P0455 a large leak and P0456 a very small leak. Check the correct fuel-cap seal where fitted, hoses, valves and the manufacturer's leak-test procedure. A loose cap is one possibility, not the only cause. Do not use compressed air or improvised flame tests around fuel vapour.
Sources and interpretation [1]
A code identifies a detected condition, not a part that must automatically be replaced.
Manufacturer communications
5Original wording in English
BUICK, CADILLAC, CHEVROLET, GMC
Reported code forms P0442
This service bulletin provides diagnostic tips/steps on testing for possible EVAP leaks in the system to correct a customer concern of an MIL Illuminated with DTCs P0442 and/or P0455 Set.
CHEVROLET
Reported code forms P0442
Emissions - General Motors has decided to conduct a voluntary emissions recall involving certain 2016-2019 model year Chevrolet Volt vehicles. The evaporative emissions pipe that connects to the inlet of the purge valve…
CHEVROLET
Reported code forms P0442
17197 01 - Service Update. Some vehicles may have contact between an evaporative emission pipe and air conditioning (A/C) hose. Over time, such contact may wear a hole into the pipe causing a malfunction indicator lamp…
CHEVROLET
Reported code forms P0442
17197 - Service Update. Some vehicles may have contact between an evaporative emission pipe and air conditioning (A/C) hose. Over time, such contact may wear a hole into the pipe causing a malfunction indicator lamp…
CHEVROLET
Reported code forms P0442
This Preliminary Information communication provides information to the technician about vehicles that have a Malfunction Indicator Lamp on. Technician will find Diagnostic Trouble Code P0442 set. Technician will need to…
Check vehicle applicability
1A listed vehicle is a research lead. Confirm the engine, production range and software in the manufacturer's information.
| Make | Model | Model year |
|---|---|---|
| Chevrolet | VOLT | 2017 |
Before replacing a part
Record codes and freeze-frame data. Check battery condition, related codes and visible wiring or hose damage. Follow the vehicle's diagnostic procedure and test results before replacing parts.
Sources and interpretation
These explanations are editorial summaries of the linked manufacturer material. PDF page numbers count from the first file page. Original publications are in English; translations are reference aids. A cited edition is not a claim that it is the manufacturer's latest instruction.
- 2024–2025 MY OBD System Operation Summary for Gasoline Engines ↗
Ford Motor Company · PDF page(s) 11, 12 ·
Source check date · 2026-10-27
Can I keep driving?
A code alone cannot establish whether driving is safe. A flashing malfunction light, severe shaking, overheating, oil-pressure warning or loss of braking or steering needs prompt attention. Stop in a safe place and seek assistance when control or engine safety is affected. Follow the vehicle handbook.