What does code P0442 mean on a Buick and is it safe to drive?
P0442: Evaporative Emission System Leak Detected (Small Leak). Here's what it means on your Buick, what usually causes it, what repairs typically cost, and how safe it is to keep driving.
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What this code means
The EVAP system has detected a small leak. Often caused by a loose or faulty gas cap or a small hose leak.
Common causes for your Buick
- Loose, damaged, or wrong gas cap
- Cracked or disconnected EVAP hose
- Faulty purge or vent valve
- Leaking charcoal canister
Symptoms
- Check Engine Light
- Often no driveability issues
Typical fixes
- Tighten or replace gas cap
- Smoke test EVAP system
- Replace damaged hoses or valves
Repair cost range
For a Buick, repairs for P0442 often fall between $15 and $300, depending on the cause and whether you use OEM or aftermarket parts. Labor rates vary by location.
Known issues on Buick
Buick P0442 shares GM's small EVAP leak diagnosis procedures. Start with the gas cap; if clear, use a smoke machine to find hose cracks at the EVAP canister or purge valve connections.
Most commonly affected models
LaCrosse 2010–2016Enclave 2008–2017Verano 2012–2017