NTK 25709 Oxygen Sensor - Downstream

Direct Fit Oxygen Sensor for Downstream Use

NTK Oxygen Sensor 25709 is a direct fit, heated oxygen sensor built for specific downstream applications. It is engineered with a 4-wire layout, 18 mm threaded mounting, and a 15.75 in. wiring harness length for a factory-style replacement on select Chevrolet Aveo, Chevrolet Aveo5, Pontiac G3, Pontiac G3 Wave, and Suzuki Swift+ models.

Key Features

• Direct fit, specific application oxygen sensor
• Heated sensor design for downstream exhaust monitoring
• 4-wire configuration for OE-style signal and heater circuit layout
• 18 mm threaded mounting type
• 15.75 in. wiring harness length
• Built for 2009-2011 Chevrolet Aveo and Aveo5, plus 2009-2010 Pontiac G3 and Suzuki Swift+

Product Details

NTK is the Sensor Specialist within the NGK family of products and focuses on OE application coverage for import and domestic vehicles. Part number 25709 reflects that approach with a direct fit design that matches the original equipment equivalent layout for downstream exhaust placement. For shoppers searching for a downstream oxygen sensor for 2009-2011 Chevrolet Aveo, 2009-2011 Chevrolet Aveo5, or 2009-2010 Pontiac G3, this sensor provides the correct threaded mounting and harness configuration for the listed applications. This part cross-references DENSO Auto Parts (e.g., 234-4298) and Delphi (e.g., ES20146) for the same application.

Common Issues This Sensor May Address

• Check engine light related to downstream oxygen sensor performance
• Fault codes tied to exhaust oxygen monitoring
• Incorrect air-fuel feedback from a worn heated O2 sensor
• Harness or connector mismatch on a direct replacement repair
• Emissions inspection failures caused by sensor degradation

Installation Notes and Tips

Verify the vehicle’s downstream sensor location before ordering and match the connector, wire count, and thread size to the original part. Confirm the exhaust bung uses an 18 mm threaded sensor and route the 15.75 in. harness away from hot exhaust components during installation. For 2009-2011 Chevrolet Aveo and Aveo5, as well as 2009-2010 Pontiac G3 and Suzuki Swift+, compare the original sensor shape and lead length to ensure a proper direct fit replacement.

Quality Assurance

NTK manufactures oxygen sensors with OE-focused engineering and extensive production testing to help maintain fit, form, and function that meet or exceed original equipment specifications. Part number 25709 is part of NTK’s direct fit oxygen sensor line, backed by the brand’s OE application expertise and manufacturing control from raw ceramic material through finished sensor production.