HTMXJA Oxygen O2 Sensor 2-Pack — Upstream & Downstream Direct-Fit for 2012–2017 Accent/Rio/Soul 2.4L

HTMXJA 2-pack oxygen sensors replace both upstream (234-5055) and downstream (234-4568) units to restore accurate exhaust monitoring on 2012–2017 Hyundai Accent, 2012–2018 Kia Rio and 2012–2016 Kia Soul with the 2.4L L4 engine.

These two direct-fit sensors are designed as OE-equivalent replacements that match factory specifications for thread, connector and response characteristics. They monitor exhaust oxygen levels before and after the catalytic converter so your engine control system can adjust fuel delivery and keep emissions within expected ranges. Each sensor is built from durable materials to withstand heat and road exposure, and the pair includes the upstream and downstream positions needed when both sensors are being changed.

How do these sensors affect engine performance and fuel economy?

Oxygen sensors provide the engine control module (ECM) with real-time exhaust gas readings. When sensors respond accurately, the ECM can maintain the correct air–fuel ratio, which helps optimize combustion stability and fuel usage. Using worn or faulty sensors can result in rough idling, higher fuel consumption or an illuminated check-engine light.

• Upstream sensor (234-5055) supplies fast-response data for air–fuel adjustments.
• Downstream sensor (234-4568) monitors catalytic converter efficiency.
• Direct-fit connectors and threads match OEM for straightforward replacement.
• High-temperature construction resists corrosion and soot buildup.

Will these sensors fit my vehicle and how do I confirm compatibility?

These HTMXJA sensors are intended for vehicles with the 2.4L L4 engine family listed in the fitment. Before ordering, verify your vehicle’s year, make, model and engine code match the compatible range. Also confirm the OEM reference numbers (234-5055 upstream, 234-4568 downstream) against your existing sensors or parts catalog to ensure an exact replacement.

• Fitment: Accent 2012–2017, Rio 2012–2018, Soul 2012–2016 — L4 2.4L.
• Reference part numbers included for cross-checking with your current sensors.
• Confirm sensor length and connector style match your vehicle harness.
• No vehicle modifications typically required when OE-equivalent.

How difficult is installation and what tools or precautions are needed?

Installation is generally straightforward for anyone with basic automotive skills and a few hand tools. The sensors screw into the exhaust bung and plug into the factory wiring harness; anti-seize or thread lubricant is often recommended for future removal. If you’re unsure, a professional technician can replace both sensors quickly and verify the system is functioning correctly.

• Standard O2 sensor socket or 22mm wrench recommended for removal/installation.
• Disconnect the battery and let the exhaust cool before working on sensors.
• Use anti-seize on threads if not pre-applied, avoiding sensor tip contamination.
• Reconnect harness securement clips to prevent wiring strain or damage.

Who this is for: Drivers and DIY mechanics who need a pair of OE-equivalent oxygen sensors to replace both upstream and downstream units on compatible Hyundai and Kia 2.4L vehicles. This kit suits routine maintenance, emissions-related troubleshooting, or whenever a faulty O2 sensor triggers diagnostic trouble codes. HTMXJA offers a six-month warranty and part references to help ensure you receive the correct sensors for your vehicle.