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Denso 234-3091 Oxygen Sensor - Upstream
Overview of Denso OE Style Oxygen Sensor 234-3091
The Denso OE Style Oxygen Sensor 234-3091 is designed specifically for Subaru vehicles, including the Forester, Impreza, and Legacy models. This heated oxygen sensor ensures accurate emissions control and optimal engine performance by monitoring exhaust gases effectively.
- Heated sensor type for faster activation and improved efficiency
- Specific fit for Subaru Forester, Impreza, and Legacy models
- Threaded mounting type with 0.708-inch thread diameter
- Female connector with 3-wire configuration
- Wiring harness length of 17.32 inches for precise installation
Detailed Product Description
The Denso 234-3091 oxygen sensor is engineered to meet the exact specifications of Subaru vehicles, providing reliable emissions feedback to the engine control unit. Featuring a heated sensor element, it reaches operating temperature quickly, which helps reduce cold start emissions and improves fuel efficiency. The sensor’s 3-wire design and female connector ensure compatibility with the vehicle’s wiring harness, while the 0.708-inch threaded mounting type allows for secure installation. With a wiring harness length of 17.32 inches, this sensor fits precisely without excess slack or tension.
This oxygen sensor is part of Denso's OE Style product line, which focuses on delivering original equipment quality and fitment. The OE Style line is designed to replicate the performance and durability of factory-installed parts, making it a suitable replacement for maintaining Subaru vehicle emissions systems.
Common Applications and Issues Addressed
- Helps maintain proper air-fuel mixture for Subaru Forester, Impreza, and Legacy
- Reduces engine misfires and rough idling caused by faulty oxygen sensors
- Prevents increased emissions and failed emissions tests
- Improves fuel economy by providing accurate exhaust gas readings
- Resolves check engine light triggers related to oxygen sensor faults
Installation Notes and Tips
- Ensure vehicle compatibility with Subaru Forester, Impreza, or Legacy before installation
- Use appropriate tools to avoid damaging the 0.708-inch threaded mounting
- Verify the female connector matches the vehicle’s wiring harness
- Handle the sensor carefully to avoid contamination of the sensing element
- Follow vehicle manufacturer torque specifications during installation
Quality Assurance and Warranty
Denso OE Style oxygen sensors are manufactured to meet strict quality standards, ensuring reliable performance and durability. The 234-3091 part number undergoes rigorous testing to comply with emissions regulations and OEM specifications. Warranty coverage details should be confirmed with the point of purchase or manufacturer documentation.
| Brand | Denso |
| Part Number | 234-3091 |
| Position | OE Style, Upstream |
| Connector Gender | Female |
| Mounting Type | Threaded |
| Sensor Type | Heated |
| Thread Diameter | 0.708 |
| Universal Or Specific Fit | Specific |
| Wire Quantity | 3 |
| Wiring Harness Length | 17.32 |
This part fits 10 vehicles. Search below:
| Year | Make | Model | Position | Notes |
|---|---|---|---|---|
| 1999 | Subaru | Forester | Upstream | OE Style |
| 1999 | Subaru | Impreza | Upstream | OE Style |
| 1999 | Subaru | Impreza | Upstream | Canada & Exc. Calif.; OE Style |
| 1999 | Subaru | Legacy | Upstream | OE Style |
| 1999 | Subaru | Legacy | Upstream | Excluding California.; OE Style |
| 1998 | Subaru | Forester | Upstream | OE Style |
| 1998 | Subaru | Impreza | Upstream | OE Style |
| 1998 | Subaru | Legacy | Upstream | OE Style |
| 1997 | Subaru | Legacy | Upstream | OE Style |
| 1996 | Subaru | Legacy | Upstream | OE Style |
* Always verify fitment with your vehicle's VIN if unsure. Submodel & trim restrictions may apply.
This part directly replaces or is cross-referenced with the following part numbers:
Cross-reference numbers are provided for identification purposes only. Always confirm fitment before ordering.