VW 4-Pin O2 Oxygen Sensor Connector – OEM 3A0973304 / 3A0973334 | Golf Passat Tiguan
Direct OEM-specification replacement for the Volkswagen 4-pin heated oxygen sensor (HO2S) connector. Cross-references OEM part numbers 3A0973304 (female/socket side) and 3A0973334 (male/plug side). Used on upstream (pre-cat) and downstream (post-cat) oxygen sensors across VAG platforms. Available bare or with 15cm pre-wired leads.
| Segment | Meaning |
|---|---|
| 3A0 | VAG platform code (VW Passat B3/B4 era) |
| 973 | Electrical connector component group |
| 304 | 4-pin female connector variant |
| 334 | 4-pin male connector variant |
| 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 |
| Attribute | Detail |
|---|---|
| Pin Count | 4-Pin |
| OEM Part Numbers | 3A0973304 / 3A0973334 |
| 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 | Volkswagen, Audi, SEAT, Škoda |
| 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 |
Q: Are terminals included?
A: Yes, terminals are included with all variants.
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4 Pin Connectors
