AIUSLN Upstream Front Oxygen Sensor for Hyundai 39210-3C100 / 2344854, Cross-border Best-selling Quality Choice

Hyundai upstream front oxygen sensor 39210-3C100 / 2344854; AIUSLN cross-border hot-selling quality; directly replaces Hyundai OEM 39210-3C100; also compatible with 39210-3C820, 39210-3C830, 39210-3C860 and interchangeable 234-4854. Core function: monitor exhaust oxygen content and feed ECU to precisely control air–fuel ratio; ensure combustion efficiency. Fits Sonata, Elantra, Tucson, etc. After installation, it solves high fuel consumption, weak acceleration, and excessive emissions. If idle is unstable or power response is slow, investigate this sensor first.