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What 15 owners told NHTSA about the 2020 Chevrolet Impala

These are the actual owner complaints behind this car’s reliability verdict, filed with the federal government, unedited. They’re unverified reports, not confirmed defects: read them as leads for your pre-purchase inspection, not a diagnosis.

All (15)Crash / fire / injury (3)Electrical system (3)Steering (3)Airbags (2)Fuel system (2)Transmission & drivetrain (2)Body & structure (1)Engine (1)Lane Departure (1)Lights (1)Seat belts (1)

2 of 15 complaints match · Fuel system · clear filters

Jun 16, 2026Fuel systemCrash

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.

NHTSA ODI 11744373

Sep 19, 2024EngineFuel system

I was driving down the highway in anchorage ak I heard a loud bang like a gunshot , when the vehicle was inspected I was told basically Evap, fuel system , fans , electrical , Cadillac converter exploded was the loud bang ! Serious issues have caused the vehicle to be inoperable !

NHTSA ODI 11615402

Working with the data? Download all 15 complaints as CSV · fetched from NHTSA July 19, 2026

How to use these: a complaint is one owner’s report, filed voluntarily and published unverified. Patterns matter more than any single story. If several owners describe the same failure at similar mileage, put that system at the top of your pre-purchase inspection list. Back to the full 2020 Chevrolet Impala verdict →