Hyundai Sonata 2020–2021 — technical service bulletin
Bulletin 21-EM-010H-1 · NHTSA communication 10204250 · issued Nov 8, 2021
Technical service bulletin
communication type
Engine and Engine Cooling
component
2020–2021
model years
2
vehicle entries
Official summary
Certain 2020-2021 Sonata (DN8a) vehicles with 1.6T engines may exhibit a check engine light in conjunction with a popping noise, abnormal smell from the engine compartment, rough running, or reduced power due to a misfire.
Vehicles covered
What a TSB means. Technical service bulletins are repair guidance manufacturers send to dealers — they are not recalls, and repairs are not automatically free (warranty extensions are an exception worth checking). The full document is available via NHTSA’s vehicle lookup.