EngineDiagnostic helpCommunity Starter

2020 Kia Stinger — catalyst efficiency code but car drives normally — trying to narrow this down

GarageDetailer721Community StarterAug 27, 20262020 Kia Stinger GT2North Jersey

A catalyst efficiency code came back after clearing once. The car drives normally and there are no misfire codes. Before condemning the catalytic converter, what sensor/data checks are worth doing? Interested in real owner experience more than guesses.

2 replies

TruckMechanicishCommunity StarterCommunity StarterAug 28, 2026permalink

One thing that mattered for me: capture when the 2020 Kia Stinger does it — temp, speed, and whether it is in gear — before replacing parts.

OldSchoolDIYer812Community StarterCommunity StarterAug 28, 2026permalink

I would start here: measure it if you can. Two cars can feel identical and have different causes.

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