2021 Kia K5 fuel/propulsion system problems
40 owner complaints filed with NHTSA name the fuel/propulsion system on the 2021 Kia K5 — 25% of all complaints for this model year.
What owners report
“Recall NNK post-repair failure. Dealership: Kia of Valdosta (RO# XXX). After ECU update NNK-02-0118, my K5 suffered a severe loss of acceleration and torque. The car cannot safely merge on highways. The dealer’s own live scan data sheet proves that at 4,997 RPM under full load, the Turbo…”
filed Jul 30, 2026
“My car is losing power upon acceleration causing a loss of power upon take off upon taking off and when gears are shifting. Told by dealer it is a problem with fuel injection. Replaced several coil packs and spark plugs on my own. Dealer repair shop had my car for 4 days for the fuel talk and valve…”
filed Jul 8, 2026
Verbatim excerpts from complaints filed with NHTSA. Reports are not independently verified.
Related service bulletins
TECHNICAL SERVICE BULLETIN: VOLUNTARY EMISSIONS SERVICE CAMPAIGN: FUEL TANK AND/OR PCSV CHECK VALVE INSPECTION/REPLACEMENT + ECU SW UPGRADE (SC288/SC288A) CLOSED & SUPERSEDED - This bulletin is now closed and superseded…
SC288_TSB_R6_CLSD · Emissions · issued Jan 16, 2026
Fuel/propulsion System problems in other K5 years
| Year | Reports | Share |
|---|---|---|
| 2024 K5 | 2 | 7% |
| 2023 K5 | 39 | 38% |
| 2022 K5 | 34 | 28% |
Other reported problem areas on the 2021 Kia K5
Counts are unique NHTSA complaints naming this component group. Complaints are unverified owner reports; mileage is computed only from complaints that included a usable odometer reading.