Denso 234-4257 Oxygen Sensor - Upstream

Denso OE Style Oxygen Sensor 234-4257

Denso 234-4257 is a heated oxygen sensor built to OE-style specifications for direct replacement in select GMC Savana 3500, Chevrolet Express 3500, and GMC Savana 2500 applications. It is engineered for a specific fit and threaded mounting, with a female connector and 4-wire design for straightforward integration.

Key Features

• Heated oxygen sensor for upstream exhaust monitoring
• Specific-fit design for the listed vehicle applications
• 4-wire configuration with female connector
• Threaded mounting type with 0.708 in. thread diameter
• 12.40 in. wiring harness length
• OE-style replacement built to match factory fit and function

OE Style Construction

Denso’s OE Style line focuses on exact replacement fitment and factory-like performance. This oxygen sensor uses a precision-built design to match the original application, helping maintain proper air-fuel feedback for the engine control system. The sensor also incorporates Denso’s aluminum oxide trap layer, which helps protect the ceramic element from silicone and lead contamination for longer service life and stable engine operation. This part number, 234-4257, is a direct replacement choice for drivers servicing upstream sensor locations on the listed GMC and Chevrolet vans.

Vehicle Fitment

• Fits 2016 GMC Savana 3500, Upstream
• Fits 2008-2012 GMC Savana 3500, Upstream
• Fits 2008-2012 Chevrolet Express 3500, Upstream
• Fits 2011-2012 GMC Savana 2500, Upstream

What It Helps Address

• Check engine light related to upstream oxygen sensor faults
• Incorrect fuel trim readings from a worn sensor
• Reduced fuel economy caused by inaccurate exhaust feedback
• Rough idle or drivability issues tied to sensor response problems
• Failed emissions testing due to oxygen sensor performance concerns

Installation Notes

Confirm the upstream sensor location before installation and verify connector style, wire count, and thread size against the original part. The threaded mounting design and specific-fit configuration are intended to match the factory application on the listed GMC Savana 3500, Chevrolet Express 3500, and GMC Savana 2500 models. Use the vehicle’s service information for proper removal and torque procedures.

Quality Assurance

Denso manufactures and tests this oxygen sensor to strict OE standards for consistent fit and performance. Part number 234-4257 is built as an OE-style replacement with the right connector, harness length, and sensor configuration for the listed applications. This part cross-references ACDelco 213-4244 and Bosch 15283 for the same application.