Denso 234-4397 Oxygen Sensor - Downstream Front
OE Quality 60-Day Returns
Denso
 OE Style

Denso 234-4397 Oxygen Sensor - Downstream Front

Brand Denso 234-4397
Position Downstream Front
Connector Gender Female
Mounting Type Threaded
Sensor Type Heated
Thread Diameter 0.708
Universal Or Specific Fit Specific
Wire Quantity 4
Wiring Harness Length 36.22
Product line OE Style
Fits Mazda · 3 vehicles

OE style replacement. Precision-built for exact replacement and a first-time fit.

Heated sensor. Helps support faster operation and consistent engine performance.

Threaded mounting. Female connector and 4-wire design for a secure connection.

Cross-references BorgWarner OS1742, Bosch 15428 and Mazda AJ5918861B for the same application. See all 8.

$77.52Free shipping
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Denso OE Style Oxygen Sensor for Mazda 6

This Denso OE Style oxygen sensor is a direct-fit replacement for the downstream front position on 2003-2005 Mazda 6 models. Built to match OE specifications, Denso 234-4397 is designed for accurate exhaust monitoring, stable engine management, and a first-time fit.

Key Features

  • Specific-fit heated oxygen sensor for the downstream front location
  • OE-style design for direct replacement on 2003-2005 Mazda 6
  • 4-wire configuration with female connector
  • Threaded mounting with 0.708 in. thread diameter
  • 36.22 in. wiring harness length for proper routing
  • Aluminum oxide trap layer helps protect the sensing element from silicone and lead contamination

Product Details

Denso 234-4397 is engineered and tested to OE standards for precise signal response and dependable operation. As part of Denso’s OE Style line, this oxygen sensor is built for exact replacement fitment and consistent performance in emissions control systems. It is a heated, specific-fit sensor intended for the downstream front position on Mazda 6 applications from 2003 through 2005. This part cross-references Bosch 15428 and NTK 22100 for the same application.

What This Oxygen Sensor Helps Address

  • Check engine light concerns related to oxygen sensor performance
  • Incorrect exhaust oxygen readings affecting fuel control
  • Reduced fuel economy caused by a worn sensor
  • Slow sensor response that can affect drivability
  • Emissions system faults on Mazda 6 models

Installation Notes and Tips

Verify the downstream front position before installation and confirm connector style, thread size, and harness length against the original sensor. Use proper oxygen sensor service tools to avoid damaging the threaded mounting area, and inspect the exhaust bung for corrosion or contamination before threading in the replacement. For 2003-2005 Mazda 6 oxygen sensor replacement, matching the OE-style connector and wire count helps ensure correct routing and fit.

Quality Assurance

Denso manufactures and tests this sensor to strict OE standards for accurate replacement fitment and dependable operation. The OE Style line is built to deliver the correct part and fit for the specified Mazda 6 application.

Related reading

This part fits 3 vehicles
Always verify fitment with your vehicle's VIN if unsure. Submodel & trim restrictions may apply.
YearMakeModelPositionNotes
2005Mazda6Downstream FrontOE Style
2004Mazda6Downstream FrontOE Style
2003Mazda6Downstream FrontOE Style
Directly replaces or cross-references 8 part numbers
Cross-reference numbers are provided for identification purposes only. Always confirm fitment before ordering.
BorgWarner — OS1742Bosch — 15428Mazda — AJ5918861BMazda — AJ5918861CNTK — 22100Standard Ignition — SG988Walker Products — 250-24715Walker Products — 350-34204