A-Premium Downstream Oxygen Sensor for Hyundai & Kia — Heated 4-Wire B1S2, Compatible with Genesis

The A-Premium downstream (B1S2) heated oxygen sensor is a direct-replacement, 4-wire threaded sensor designed to restore accurate exhaust O2 readings for select Hyundai and Kia models.

This downstream oxygen sensor monitors exhaust gas after the catalytic converter to help the engine management system evaluate catalyst performance and adjust fuel trims. Built as a heated, threaded unit with a male connector and supplied in a protective box, this A-Premium sensor matches the electrical and mounting specifications required by many 2010–2016 Hyundai and Kia vehicles. Always confirm fitment with your vehicle details before ordering.

Which vehicles does this sensor fit?

This sensor fits various Hyundai and Kia models across multiple model years as the downstream (bank 1 sensor 2) replacement. Compatibility differs slightly by emissions type and model year, so check exact match using your car’s year, engine, and transmission.

• Hyundai Sonata: 2009–2015 variants listed (2.4L, includes FHEV and specific dates for gas models)
• Tucson and Sportage: several 2010–2016 2.0L and 2.4L fitments (automatic and some manual cases)
• Genesis Coupe, Santa Fe, Santa Fe Sport, Optima, Sorento, Forte and Forte Koup across 2010–2016
• Note: Does not fit federal emissions models in certain years; verify using vehicle entry at listing

What are the technical specifications I should know?

The A-Premium sensor is built with the connector, wire count, and mounting style common to OEM downstream sensors for these makes. It’s a heated sensor with four wires, threaded mount, and a male connector for reliable electrical coupling.

• Wire quantity: 4 (heated sensor design)
• Mounting: threaded for standard downstream port installation
• Connector gender: male; supplied as a single sensor in a box
• Reference numbers often used for cross-checking: 250-24878, 350-34630, 25024878, 35034630

How will installing this sensor affect my vehicle’s performance?

Replacing a failing downstream O2 sensor helps the vehicle’s ECU accurately monitor catalytic converter efficiency and maintain correct emissions feedback. While it does not tune power directly, a functioning downstream sensor supports stable fuel trim calculations and emissions diagnostics.

• Restores accurate post-catalyst oxygen readings to the ECU
• Helps prevent false catalyst or emission fault codes when sensor is faulty
• Supports proper long-term fuel trim adjustments and emissions reporting

What should I check before buying and installing?

Confirming the correct fitment prevents returns and ensures plug-and-play replacement. Check your vehicle year, engine displacement, transmission type, and emissions region; the listing’s vehicle selector or your OEM part cross-reference numbers are the best verification tools.

• Enter vehicle year, make, model, engine, and transmission in the listing selector
• Compare OEM reference numbers (listed above) with your existing part
• Inspect connector orientation and wire routing for a proper match before install

Who is this for: This A-Premium downstream oxygen sensor is intended for DIYers and professional mechanics needing a direct-fit replacement for Hyundai and Kia models listed above. It suits owners troubleshooting emissions-related trouble codes, replacing a physically damaged sensor, or restoring correct catalyst monitoring after repairs. If you’re unsure about fitment, provide your VIN or use the vehicle selector on the product page to confirm compatibility before purchase.