2020 Chevrolet Impala

The component is the Evaporative Emission Control System (EVAP) Vapor Canister Purge Valve.The internal diaphragm or solenoid of the factory-installed purge valve has worn out prematurely or became contaminated, locking it permanently into a stuck-open position.The Manifestation or (Symptoms): The stuck-open valve continuously drafts raw fuel vapor and unmetered air into the engine intake manifold. This causes an improper air-fuel mixture, resulting in:Stumbling / Failure to Start Immediately After Refueling (the engine is flooded by gas tank vapors forced in during fill-up).Rough Idling (due to a continuous vacuum leak).Illuminated Check Engine Light tracking Diagnostic Trouble Codes (DTCs) P0496 (High Purge Flow) or P0442. Yes, it is available for inspection. The vehicle stumbles, hesitates, and fails to restart at busy gas pumps and intersections which places drivers, passengers, and other motorists at an immediate risk of a collision. Yes, the problem has been validated by an professional auto mechanic shop. No, it has not been inspected by anyone else other than the mechanicshop to diagnose the problem, issue. The check engine light came on as I cranked the vehicle up and it started idling. No known symptoms until check engine came on prior to failing. The check engine light first appeared in May 2026 as well as the codes mentioned above.