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NTK 21551 Oxygen Sensor - Downstream
| Brand | NTK 21551 |
|---|---|
| Position | Downstream |
| Wiring Harness Length | 12.7500 |
| Sensor Type | Heated |
| Universal Or Specific Fit | Specific |
| Wire Quantity | 4 |
| Thread Diameter | 18.000 |
| Mounting Type | Threaded |
| Product line | Direct Fit Oxygen Sensor |
| Fits | Buick · 1 vehicle |
Direct fit design. Built for specific application coverage and OE-style replacement.
Heated sensor. Supports faster operating readiness for accurate exhaust monitoring.
OE-level testing. Extensively tested during manufacturing for quality and reliability.
Cross-references BBB Industries 13423, Delphi ES20010 and 75-1703 for the same application. See all 9.
Will it fit your vehicle?
Free return shipping if it doesn't fit.
Direct Fit Oxygen Sensor Overview
NTK 21551 is a direct fit oxygen sensor built for specific applications and engineered for accurate exhaust monitoring. It is a heated, threaded sensor with a 4-wire design and a 12.75-inch harness for a precise replacement on the listed application.
Key Features
- Direct fit design for specific application coverage
- Heated oxygen sensor for faster operating readiness
- 4-wire configuration for the correct signal setup
- Threaded mounting with 18 mm thread diameter
- 12.75-inch wiring harness length
Detailed Description
NTK 21551 is part of the Direct Fit Oxygen Sensor line, which focuses on application-specific replacement parts with OE-style fit, form, and function. NTK is known for oxygen sensor manufacturing and uses ceramic-based technology and manufacturing controls to support consistent sensor performance. This part cross-references Delphi ES20010 and BBB Industries 13423 for the same application.
Fits 1994 Buick Regal, downstream. For buyers searching for a 1994 Buick Regal downstream oxygen sensor, this NTK 21551 replacement matches the listed configuration and mounting style. It is a practical choice when replacing a worn sensor on the Buick Regal with the correct threaded, heated, specific-fit design.
Common Replacement Reasons
- Check engine light related to oxygen sensor performance
- Incorrect air-fuel feedback from a failing sensor
- Slow sensor response during closed-loop operation
- Damaged wiring or connector wear on the original unit
- Exhaust emissions issues tied to sensor degradation
Installation Notes and Tips
Confirm the downstream location, 4-wire configuration, and 18 mm threaded mounting before installation. Match the harness length and connector style to the original sensor on the vehicle. Use the vehicle service information for proper removal and installation procedures.
Quality Assurance
NTK states that its oxygen sensors are extensively tested during manufacturing to help ensure quality and reliability that meet or exceed OE specifications.
| Year | Make | Model | Liters | Cylinders | Position | Notes |
|---|---|---|---|---|---|---|
| 1994 | Buick | Regal | 3.8L | V6 | Downstream | Downstream oxygen sensor with original equipment equivalent design; Direct Fit Oxygen Sensor |
| No rows match your filter. | ||||||