P0442 on Chevrolet
Evaporative Emission Control System Leak Detected (Small Leak)
P0442 on Chevrolet vehicles indicates evaporative emission control system leak detected (small leak). Au7o has documented this code across 5 Chevrolet models — most commonly on Equinox, HHR, Malibu. This emissions code means the evaporative emission (EVAP) control system has detected a small leak. The EVAP system seals the fuel tank and captures gasoline vapors, routing them to be burned in the engine instead of escaping into the air, and the computer periodically pressure- or vacuum-tests the system to confirm it's sealed. A small leak the size of about a 0.040-inch hole will set this code. By far the most common and cheapest cause is a loose, damaged, or missing gas cap, so that's the first thing to check, though any cracked hose or worn seal in the system can also trigger it. Typical repair costs on Chevrolet range from $20 to $500, depending on the specific model and root cause.
Common Causes of P0442
- •Loose, damaged, or missing fuel filler cap
- •Worn or cracked gas cap seal
- •Cracked or disconnected EVAP hose or line
- •Faulty purge valve or vent valve
- •Damaged O-ring or seal at the fuel tank or filler neck
- •Small crack in the charcoal canister
- •Leaking fuel tank sending unit gasket
P0442 on Chevrolet by Model
Chevrolet Equinox(1 issue)
- P0442 — Small EVAP Leak from Gas Cap Seal, Purge/Vent Solenoid, or Rusted EVAP Line2010-2020
P0442 sets when the ECM detects a small evaporative-system leak — roughly a 0.020–0.040 inch hole's worth of pressure loss. On the Equinox this code follows a clear hierarchy of culprits. The single most common cause across all years is a degraded gas-cap O-ring that no longer seals (or a cap not clicked tight after refueling). On the second-generation 2.4L (LEA/LAF) and V6 models, the next most frequent offenders are the EVAP purge solenoid and the canister vent solenoid, which stick or leak internally. A cause that is distinctly an Equinox/Terrain pattern — especially in salt-belt states — is the metal EVAP line running under the driver's-side frame rail rusting through, which no amount of solenoid or gas-cap replacement will fix.
Chevrolet HHR(1 issue)
- Fuel Line Corrosion and Leak Near Rear Wheel2006-2011
The HHR has a documented issue with fuel line corrosion, particularly in rust belt states. The fuel line corrodes just forward of the driver-side rear wheel, developing leaks that create a fire hazard. Road salt and debris accelerate the corrosion. The issue is most commonly seen on vehicles in the northeastern and midwestern United States where road salt is used heavily in winter.
Chevrolet Malibu(1 issue)
- P0442 — Small EVAP Leak from Gas Cap O-Ring or Purge Valve (Capless Filler Seal on 2016+)2012-2023
P0442 flags a small EVAP leak (roughly a 0.020-0.040 inch hole). On 2012-2016 Malibus with a conventional threaded gas cap, the most common cause is a cracked or flattened cap O-ring. On the 2016+ ninth-gen cars with the capless fuel filler, the culprit is usually the filler-neck seal or debris holding the spring-loaded flap slightly open. On all years, a leaking or weak EVAP purge valve — a well-known failure across GM platforms of this era — is the next most likely source. Cracked charcoal-canister hoses round out the list.
Chevrolet Silverado 1500(1 issue)
- EVAP Vent Solenoid Clogging With Dust/Water Causing Check Engine Light and Hard Refueling2000-2007
A very common GMT800 Silverado problem is contamination of the EVAP canister vent valve/solenoid by dust, road debris, or water intrusion. When the vent cannot flow properly, the truck sets EVAP leak or vent performance codes and may repeatedly shut off the gas pump during refueling. GM issued service bulletins and updated vent relocation kits for trucks used in dusty environments.
Chevrolet Traverse(1 issue)
- EVAP Purge Valve Failure Causing Rough Idle, Stalling and Hard Starts (P0496) — GM Special Coverage N2323953002019
On the 3.6L V6 (RPO LFY) Traverse, the evaporative emissions purge valve can fail to fully close, allowing fuel vapor to flood the intake. This causes a P0496 (EVAP high purge flow) code with rough running, hesitation, or stalling at idle, and hard starting after refueling. GM acknowledged the condition and issued Special Coverage N232395300 (15 years / 150,000 miles) to replace the purge valve at no charge on affected 2019 Traverse units.
Looking for P0442 on a different make?
View P0442 across all makes →Frequently Asked Questions
What does P0442 mean on Chevrolet?▼
P0442 stands for "Evaporative Emission Control System Leak Detected (Small Leak)." This emissions code means the evaporative emission (EVAP) control system has detected a small leak. The EVAP system seals the fuel tank and captures gasoline vapors, routing them to be burned in the engine instead of escaping into the air, and the computer periodically pressure- or vacuum-tests the system to confirm it's sealed. A small leak the size of about a 0.040-inch hole will set this code. By far the most common and cheapest cause is a loose, damaged, or missing gas cap, so that's the first thing to check, though any cracked hose or worn seal in the system can also trigger it. On Chevrolet specifically, this code is documented across 5 models.
What causes P0442 on Chevrolet vehicles?▼
Common causes on Chevrolet: Loose, damaged, or missing fuel filler cap, Worn or cracked gas cap seal, Cracked or disconnected EVAP hose or line, Faulty purge valve or vent valve, Damaged O-ring or seal at the fuel tank or filler neck. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0442 on a Chevrolet?▼
Repair costs on Chevrolet range from $20 to $500, depending on the specific model and root cause.
Which Chevrolet models have P0442 documented?▼
Au7o has documented P0442 on 5 Chevrolet models: Equinox, HHR, Malibu, Silverado 1500, Traverse.