Denso 234-4445 Oxygen Sensor - Downstream

Denso OE Style Oxygen Sensor for Subaru

Denso 234-4445 is an OE Style heated oxygen sensor built for specific-fit replacement on select Subaru and Saab applications. It is engineered for downstream exhaust monitoring, with a threaded mounting design and a 4-wire male connector for direct replacement service.

Key Features

• Heated oxygen sensor for downstream exhaust placement
• Specific-fit design for direct replacement on listed vehicles
• 4-wire configuration with male connector
• Threaded mounting type with 0.708 in. thread diameter
• 20.87 in. wiring harness length
• OE Style construction for accurate fit and function

OE Style Construction

Denso’s OE Style line is built to match original equipment dimensions and electrical requirements for a first-time fit. The sensor uses an aluminum oxide trap layer to help protect the ceramic element from silicone and lead contamination, supporting stable exhaust feedback, consistent engine operation, and long service life. This Denso oxygen sensor is a direct replacement for Subaru Legacy, Subaru Outback, Subaru Impreza, Subaru Forester, and Saab 9-2X downstream applications.

This part cross-references Bosch (e.g., 15170, 15172) for the same application.

Vehicle Fitment

• Fits 2006-2012 Subaru Legacy, Downstream, OE Style
• Fits 2006-2012 Subaru Outback, Downstream, OE Style
• Fits 2006-2011 Subaru Impreza, Downstream, OE Style
• Fits 2006-2010 Subaru Forester, Downstream, OE Style
• Fits 2006 Saab 9-2X, Downstream, OE Style

Common Replacement Reasons

• Check engine light related to oxygen sensor performance
• Slow or inaccurate downstream exhaust readings
• Rough fuel control caused by a failing sensor
• Reduced fuel economy from degraded sensor response
• Corrosion or contamination at the original sensor

Installation Notes

Confirm the downstream sensor location before ordering and match the connector, wire count, and thread size to the original part. Use proper oxygen sensor service tools to avoid damaging the exhaust bung or wiring harness. Verify the connector routing and harness length during installation on Subaru Legacy, Outback, Impreza, Forester, and Saab 9-2X applications.

Quality Assurance

Denso manufactures and tests this sensor to OE standards for precise replacement fit and dependable operation. Part number 234-4445 is designed to meet the original application requirements for listed Subaru and Saab vehicles.