NTK 27021 Air / Fuel Ratio Sensor - Upstream Left

Direct-Fit Air/Fuel Sensor

NTK 27021 is a direct-fit air/fuel ratio sensor for specific Ford Transit applications. It uses a heated, 5-wire design and is built for precise exhaust feedback in OE-style replacement service.

Key Features

• Direct-fit design for specific applications
• Heated sensor with 5-wire construction
• 17.5-inch wiring harness length
• 18.000 mm thread diameter with 0.38 thread length
• Specific-fit replacement, not universal

Detailed Description

NTK 27021 is part of the Direct Fit 5-Wire A/F Sensor line, engineered for straightforward replacement where the original sensor uses the same configuration. NTK is known for oxygen and air/fuel sensing technology, and this sensor reflects that focus with OE-style fit, form, and function. It is a heated sensor with a specific-fit design, making it suitable for service work on Ford Transit-150, Transit-250, Transit-350, and Transit-350 HD applications listed below. This part cross-references GK4Z9F472A for the same application.

What It Is Used For

• Replacing a worn or slow-responding air/fuel ratio sensor
• Restoring accurate exhaust mixture feedback to the engine control system
• Addressing sensor-related fault codes tied to mixture monitoring
• Correcting drivability issues caused by inaccurate oxygen sensing

Installation Notes and Tips

Verify the connector, thread size, and harness length before installation. This sensor is listed as a specific-fit part and should be matched to the exact vehicle application and sensor location shown in the fitment data. The mounting bracket is not included.

Quality Assurance

NTK manufactures oxygen sensors with extensive testing during production to meet or exceed OE specifications. The brand is part of the NGK family of products and is recognized for OE application technology and broad coverage.