Hyundai check engine codes
Overview
Hyundai models commonly show catalytic converter, EVAP, and misfire codes. Some Theta II four cylinder engines were subject to engine recalls and extended warranties.
Codes notably common on Hyundai
- P0420 Catalyst System Efficiency Below Threshold (Bank 1) · Hyundai notes
- P0300 Random or Multiple Cylinder Misfire Detected · Hyundai notes
- P0171 System Too Lean (Bank 1)
- P0442 Evaporative Emission System Small Leak Detected
Hyundai specific notes
- Hyundai extended engine coverage to 15 years or 150,000 miles for connecting rod bearing failure on certain Theta II, Nu, and Gamma engines through a class action settlement, and offers lifetime coverage on some earlier Theta II engines. A Knock Sensor Detection System software update is generally required. Check your VIN with Hyundai and NHTSA.
Owner's manuals
Official Hyundai owner's manual / owner portal (manufacturer site; we do not host copies).
Repair manuals
Step-by-step service manuals for Hyundai with torque specs and wiring diagrams:
Haynes manuals for Hyundai Chilton manuals
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Recall lookup
Check open Hyundai recalls with your VIN at the NHTSA recall lookup.
Sources
- https://www.hma-e2settlement.com/
- https://static.nhtsa.gov/odi/tsbs/2022/MC-10207801-0001.pdf
- https://www.nhtsa.gov/recalls
Sources checked October 2026. Bulletins apply only to the models and years they list.
All other codes
These work the same on Hyundai as on any vehicle:
P0430 P0301 P0302 P0303 P0304 P0174 P0440 P0455 P0456 P0128 P0135 P0141 P0101 P0299 P2135 P0401