Hyundai / Kia 4-Pin Oxygen Sensor Connector – OEM | HO2S Harness
Direct OEM-specification replacement for the Hyundai and Kia 4-pin heated oxygen sensor (HO2S) connector. Used on upstream (pre-cat) and downstream (post-cat) oxygen sensors across Hyundai and Kia petrol engine platforms. Available bare or with 15cm pre-wired leads.
4-Pin HO2S Circuit Function
| Pin |
Function |
Failure Symptom if Corroded |
| 1 |
Heater element power (+12V switched) |
P0135 / P0141 — O2 sensor heater circuit malfunction |
| 2 |
Heater element ground |
Slow O2 warm-up, rich running when cold |
| 3 |
O2 signal output to ECU (0–1V) |
P0130–P0167 — O2 sensor circuit fault, poor fuel economy |
| 4 |
Signal ground / reference |
Erratic O2 reading, ECU unable to trim fuel |
Key Specifications
| Attribute |
Detail |
| Pin Count |
4-Pin |
| Housing Material |
High-temp nylon (PA66), waterproof sealed |
| Wire Option |
Bare connector / 15cm pre-wired leads |
| Application |
Heated oxygen sensor (HO2S) harness — upstream and downstream |
| Compatible Brands |
Hyundai, Kia |
Fault Codes This Connector Fixes
| Code |
Description |
| P0130 |
O2 sensor circuit — Bank 1, Sensor 1 |
| P0136 |
O2 sensor circuit — Bank 1, Sensor 2 |
| P0135 |
O2 sensor heater circuit — Bank 1, Sensor 1 |
| P0141 |
O2 sensor heater circuit — Bank 1, Sensor 2 |
| P0150 |
O2 sensor circuit — Bank 2, Sensor 1 |
Compatible Applications
- Hyundai Sonata (YF/LF/DN8) – Upstream and downstream O2 sensor harness
- Hyundai Tucson (LM/TL/NX4) – Oxygen sensor connector
- Kia Sportage (SL/QL/NQ5) – HO2S harness
- Kia K5 / Optima (TF/JF/DL3) – O2 sensor connector
- Hyundai Elantra (MD/AD/CN7) – Oxygen sensor harness
Frequently Asked Questions
Q: Are terminals included?
A: Yes, terminals are included with all variants.