The EVAP system prevents fuel vapors from escaping into the atmosphere. A leak somewhere in the system (fuel tank, lines, canister, etc.) or a malfunctioning pump will trigger this code.
To diagnose the problem, you'll likely need to:
* Check all hoses and connections within the EVAP system for cracks, leaks, or loose fittings. This often involves inspecting the fuel tank, gas cap, purge valve, and the charcoal canister.
* Inspect the gas cap to make sure it's sealing properly. Sometimes a loose or damaged gas cap is the culprit.
* Test the EVAP purge valve. This valve controls the flow of fuel vapors. A malfunctioning valve is a common cause.
* Check the vapor pressure sensor (if your vehicle has one; some '95 Blazers may not).
It's generally recommended to take the Blazer to a mechanic for diagnosis and repair, as locating a leak in the EVAP system can be challenging. A proper scan tool will also help to pinpoint the exact location of the problem.
