NTK 21040 Oxygen Sensor - Upstream

Direct Fit Oxygen Sensor for OE Replacement

NTK 21040 is a direct fit oxygen sensor built for specific upstream applications on select Chevrolet, GMC, Pontiac, Oldsmobile, and Saturn vehicles. It uses a 2-wire, non-heated design with a threaded mounting style and a 15.2500-inch wiring harness length for a precise replacement on the listed applications.

For drivers searching for an upstream oxygen sensor for a 2000-2003 Chevrolet S10 or 2000-2003 GMC Sonoma, NTK 21040 provides a specific-fit solution that matches the original application layout. The part number 21040 is also referenced for several 2000-2002 Chevrolet Cavalier and Pontiac Sunfire applications.

Key Features

• Direct fit oxygen sensor for specific OE applications
• Non-heated sensor design
• 2-wire configuration
• Threaded mounting type with 18.000 thread diameter
• 15.2500-inch wiring harness length
• Upstream Bank 1 Sensor 1 placement on listed vehicles
• Cross-references include Bosch 13191 and DENSO Auto Parts 234-2060

Product Details

NTK Direct Fit Oxygen Sensor 21040 is part of NTK’s OE-focused sensor line, developed with ceramics expertise and manufacturing control from raw material through finished sensor. NTK supplies oxygen sensors for import and domestic applications, and this part is manufactured and tested to meet or exceed OE specifications for fit, form, and function. If you need an upstream oxygen sensor for a 2000-2001 Oldsmobile Alero, 2000-2001 Pontiac Grand Am, or 2000 Saturn LS, this part number 21040 is listed for those applications.

This part cross-references Bosch 13191 and DENSO Auto Parts 234-2060 for the same application.

Common Issues This Part Can Address

• Check engine light related to oxygen sensor performance
• Incorrect air-fuel mixture readings from a failing upstream sensor
• Reduced fuel economy caused by inaccurate exhaust oxygen feedback
• Rough idle or drivability concerns tied to sensor signal loss
• Emission test failures linked to a worn oxygen sensor

Installation Notes and Fitment

Compatible With 2000-2003 Chevrolet S10, upstream Bank 1 Sensor 1 oxygen sensor; 2000-2003 GMC Sonoma, upstream Bank 1 Sensor 1 oxygen sensor; 2000-2002 Chevrolet Cavalier, upstream Bank 1 Sensor 1 oxygen sensor; 2000-2002 Pontiac Sunfire, upstream Bank 1 Sensor 1 oxygen sensor; 2000-2001 Oldsmobile Alero, upstream Bank 1 Sensor 1 oxygen sensor; 2000-2001 Pontiac Grand Am, upstream Bank 1 Sensor 1 oxygen sensor; 2001 Saturn L100, upstream Bank 1 Sensor 1 oxygen sensor; 2001 Saturn L200, upstream Bank 1 Sensor 1 oxygen sensor; 2001 Saturn LW200, upstream Bank 1 Sensor 1 oxygen sensor; 2000 Saturn LS, upstream Bank 1 Sensor 1 oxygen sensor; 2000 Saturn LS1, upstream Bank 1 Sensor 1 oxygen sensor; and 2000 Saturn LW1, upstream Bank 1 Sensor 1 oxygen sensor.

Verify connector routing, thread size, and upstream Bank 1 Sensor 1 location before installation. Use the vehicle’s original sensor position and harness path as the reference for replacement on the listed Chevrolet S10, GMC Sonoma, and Saturn applications.

Quality Assurance

NTK is a major original equipment oxygen sensor manufacturer, and this direct fit sensor is extensively tested during production to support OE-level reliability and application accuracy. The NTK 21040 is built for specific vehicle coverage and consistent sensor performance on the listed applications.