P0442 on Buick
Evaporative Emission Control System Leak Detected (Small Leak)
P0442 on Buick vehicles indicates evaporative emission control system leak detected (small leak). Au7o has documented this code across 1 Buick model — most commonly on Encore. 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.
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 Buick by Model
Buick Encore(1 issue)
- EVAP Purge Valve May Not Fully Close (Special Coverage N232395300)2020
GM Special Coverage N232395300 identifies certain 2020 Buick Encore vehicles with the 1.4L LUV engine whose evaporative-emissions purge valve may not fully close. The engine can run rough, hesitate or stall at idle, the check-engine light can illuminate and an EVAP or fuel-trim DTC can set.
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View P0442 across all makes →Frequently Asked Questions
What does P0442 mean on Buick?▼
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 Buick specifically, this code is documented across 1 model.
What causes P0442 on Buick vehicles?▼
Common causes on Buick: 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 Buick?▼
Repair costs vary widely depending on the root cause and specific Buick model.
Which Buick models have P0442 documented?▼
Au7o has documented P0442 on 1 Buick model: Encore.