Saturn L300 evap system issue with fuel backup in filler tube and error code, possible valve or carbon canister replacement needed on Saturn L300

Some Saturn L300 owners report experiencing fuel backup in the filler tube along with error code P0455, which indicates a gross leak in the EVAP system. This issue may stem from various components within the EVAP system, such as a loose or damaged gas cap, faulty purge valve, or cracked hoses. In some cases, owners find that charcoal pellets from the canister can lead to blockages, exacerbating fuel backup problems. If the issue persists despite checking the gas cap and hoses, it may be necessary to inspect and potentially replace the EVAP vent solenoid valve, purge valve, or charcoal canister. To accurately diagnose the problem, thorough inspection for leaks and blockages is recommended, and repair costs can vary based on the severity of the issue. Consulting with a mechanic is advisable to determine the necessary repairs and associated costs.