NTK 25157 Oxygen Sensor - Downstream

Direct Fit Oxygen Sensor for Kia Rio

The NTK 25157 is a direct fit heated oxygen sensor for the downstream position on select 2001-2003 Kia Rio models. Built as a specific-fit replacement, it follows OE-style mounting and wiring requirements for a straightforward service replacement.

Key Features

• Direct fit oxygen sensor for the downstream location
• Heated sensor design for faster operating response
• Specific fit application for select Kia Rio models
• 4-wire configuration with a 17.0 in. wiring harness
• 18 mm threaded mounting type
• NTK part number 25157

Product Details

NTK 25157 is part of the Direct Fit Oxygen Sensor line, which focuses on OE-style replacement coverage and application-specific fitment. NTK uses ceramic sensor technology and extensive manufacturing testing to help maintain fit, form, and function consistent with original equipment requirements. This sensor is listed for 2001-2003 Kia Rio downstream applications and is a direct replacement choice for service work on the Kia Rio exhaust monitoring system.

This part cross-references Bosch 15536 for the same application.

What It Helps Address

• Check engine light related to downstream oxygen sensor faults
• Incorrect oxygen sensor voltage or slow sensor response
• Emissions test failures tied to sensor performance
• Fuel control issues caused by inaccurate exhaust feedback
• Replacement needs after sensor aging, contamination, or wiring wear

Installation Notes

Compatible With 2001-2003 Kia Rio, downstream. Verify connector style, harness routing, and thread size before installation. The sensor uses a threaded mounting type and a 4-wire heated design, so matching the original application is important for proper operation. Part number 25157 should be confirmed against the vehicle’s original sensor location and engine configuration before service.

Quality Assurance

NTK is a major original equipment oxygen sensor manufacturer and supplies sensors built to meet or exceed OE specifications. Each sensor is tested during manufacturing to support reliable operation and consistent application coverage.