NGK Honda S2000 2003-2000 Direct Fit Oxygen Sensor

OEM-Sourced Downstream O2 Sensor Built to Honda's Exact Specifications for the 2000-2003 S2000

The NTK/NGK 24287 is a direct-fit downstream oxygen sensor designed specifically for the 2000-2003 Honda S2000 AP1 with the F20C 2.0L VTEC engine. NTK (Nippon Tokushu Togyo Kabushiki-gaisha) is the world's largest OEM oxygen sensor manufacturer, supplying original equipment sensors to Honda, Toyota, General Motors, Ford, and virtually every major automaker.

The 24287 is engineered to Honda's original dimensional, electrical, and ceramic element specifications, meaning it slots into the factory bung, connects to the factory wiring harness, and delivers the same 0 to 1 volt switching signal the ECU expects from the downstream sensor. No adapter, no splicing, no programming. A correctly functioning downstream O2 sensor is essential for closed-loop fuel trim accuracy and for preventing false OBDII catalytic converter efficiency codes (P0420) that can result from a lazy or failed sensor rather than an actual catalyst problem.

Key Features

• Direct OEM-fit replacement for the downstream oxygen sensor on 2000-2003 Honda S2000 AP1 with F20C 2.0L VTEC
• Manufactured by NTK, the world's largest OEM oxygen sensor supplier and original Honda supplier
• 4-wire heated sensor with blade terminal connector for direct plug-and-play fitment into the factory harness
• Screw-on M18x1.5 thread for direct installation into the factory bung
• Ceramic element manufactured using NTK's proprietary raw-material-to-finished-product ceramics process for precise, consistent switching signal
• Maintains accurate closed-loop fuel trim feedback and prevents false P0420 catalytic converter efficiency codes
• Backed by NTK 1-year limited warranty

Fitment

Specifications

What's Included

• 1 x NTK 24287 direct-fit downstream oxygen sensor
• Installation instructions

About NTK / NGK

NTK is the sensors and technical ceramics division of NGK Spark Plugs, a Japanese manufacturer founded in 1936. NTK supplies oxygen sensors as original equipment to Honda, Toyota, Subaru, General Motors, Ford, Volkswagen, and dozens of other automakers worldwide. Their position as the world's largest OEM oxygen sensor manufacturer means the 24287 is produced with the same materials, tooling, and quality standards as the sensor that came out of the S2000 at the factory. NTK backs the 24287 with a 1-year limited warranty against defects in materials and workmanship.

Frequently Asked Questions

What diagnostic codes does a failed downstream O2 sensor trigger on the S2000?

A failing downstream sensor on the S2000 most commonly triggers P0136 (O2 sensor circuit malfunction, bank 1 sensor 2), P0137 (O2 sensor circuit low voltage), P0138 (O2 sensor circuit high voltage), or P0420 (catalyst system efficiency below threshold). A lazy downstream sensor that oscillates too slowly or shows a stuck signal will cause the ECU to flag a P0420 catalyst efficiency code even if the catalytic converter itself is functioning correctly. Replacing the 24287 with a new NTK sensor is the correct first diagnostic step before condemning the catalyst.

Is the NGK 24287 the upstream or downstream sensor on the S2000?

The 24287 is the downstream sensor, located after the catalytic converter. The S2000 uses two oxygen sensors: an upstream sensor (also called sensor 1 or the air/fuel ratio sensor, located before the catalyst) and a downstream sensor (sensor 2, located after the catalyst). The 24287 replaces the downstream sensor only. Verify which sensor is failing using your scan tool before ordering.

Will the NGK 24287 plug directly into the S2000 factory wiring harness?

Yes. The 24287 is engineered as a direct OE-fit replacement with the same blade terminal connector, wire gauge, and pigtail length as the original Honda-supplied sensor. No splicing, adapters, or harness modification is required. Simply unscrew the old sensor, thread in the new 24287, and plug in the connector.

Do I need a sensor thread chaser or anti-seize before installing the 24287?

If the old sensor has been in place for several years, the M18x1.5 bung threads may have rust or corrosion. Cleaning the bung threads with a thread chaser before installation is recommended to ensure the new sensor seats correctly. A small amount of anti-seize compound applied to the threads (avoiding the first two threads nearest the tip) makes future removal significantly easier. Do not apply anti-seize to the sensor element or the first two threads, as it can affect electrical continuity.

How long does it take to replace the downstream O2 sensor on the S2000?

On most S2000s the downstream sensor is accessible from above with the vehicle safely raised on stands. With the engine cooled, the job typically takes 30 to 45 minutes for an experienced DIYer using a standard O2 sensor socket and breaker bar. If the sensor has not been replaced before, corrosion on the bung threads can increase removal time significantly. Penetrating oil applied and allowed to soak overnight will help free a stuck sensor.

What is the difference between the upstream and downstream sensor on the S2000?

The upstream sensor (before the catalyst) is a wideband air/fuel ratio sensor used for primary fuel control, providing a continuous voltage signal the ECU uses to adjust injector pulse width in real time. The downstream sensor (the 24287) is a narrowband switching sensor positioned after the catalyst that primarily monitors catalyst efficiency. Its signal switches between low voltage (rich) and high voltage (lean) at a slower rate than the upstream sensor. If the downstream signal mimics the upstream signal too closely, the ECU interprets this as catalyst failure.

Can a bad downstream O2 sensor cause reduced fuel economy on the S2000?

A failed downstream sensor by itself typically does not cause significant fuel economy changes, since the ECU primarily uses the upstream sensor for fuel trims. However, if the ECU enters a default or limp mode due to a stored fault code affecting fuel control, economy can be impacted. Additionally, if a P0420 code causes the driver to delay addressing the issue and the catalyst has genuinely degraded, fuel efficiency and power can both suffer. Prompt replacement of the 24287 is the correct step to restore proper OBDII monitoring.

Is the NTK 24287 the same part as the Honda OEM sensor?

NTK is an OEM supplier to Honda, meaning NTK manufactures sensors that meet Honda's original design specifications. The 24287 is produced to the same material and dimensional standards as the OEM unit. While the part number differs from Honda's OEM service part number, the sensor meets the fit, function, and signal characteristics of the original Honda-supplied downstream O2 sensor for the 2000-2003 S2000.

Installation Instructions

1. Allow the exhaust system to cool completely before beginning. Working on a hot exhaust is a burn hazard.
2. Safely raise and support the vehicle on jack stands. The downstream O2 sensor on the S2000 is located on the exhaust pipe after the catalytic converter.
3. Disconnect the sensor's wiring harness connector. Press the release tab and pull straight back from the connector body. Do not yank the wiring.
4. Apply penetrating oil to the sensor base threads if there is visible rust or corrosion. Allow to soak for at least 15 minutes before attempting removal.
5. Using an O2 sensor socket (typically 22mm with a wire slot), break the sensor loose counterclockwise. If the sensor is heavily seized, apply heat to the bung using a torch before attempting removal — not to the sensor itself.
6. Clean the bung threads with a thread chaser or wire brush. Verify thread condition before installing the new sensor.
7. Apply a small amount of anti-seize compound to the sensor threads, avoiding the first two threads near the tip and the sensor element.
8. Thread the new NTK 24287 in by hand first, then torque to approximately 33-40 ft-lbs using the O2 sensor socket.
9. Route the sensor wiring away from exhaust heat and moving components, then plug the factory harness connector into the new sensor until it clicks.
10. Start the vehicle and allow it to reach operating temperature. Clear any stored fault codes with a scan tool and perform a drive cycle to confirm the sensor is operating correctly and no codes return.

WARNING: This product can expose you to chemicals including lead and phthalates, which are known to the State of California to cause cancer and reproductive harm. For more information go to www.P65Warnings.ca.gov.