Spectra OS5381 Oxygen Sensor - Downstream or Upstream

Spectra OS5381 Oxygen Sensor

The Spectra OS5381 oxygen sensor is a direct-fit emission control replacement for select Mazda and Kia applications. It is built to match original equipment performance targets for accurate exhaust feedback and stable engine management.

• Oxygen sensor for emission control and air-fuel monitoring
• OE-style replacement for select Mazda Protege, Mazda MX-3, and Kia Sephia applications
• Supports upstream and downstream positions where listed
• Manufactured with quality control processes to meet or exceed OE replacement expectations
• Cross-references Bosch 13362 and Delphi ES10366 for the same application

Detailed Application Coverage

Compatible with 1995-1998 Mazda Protege, upstream; 1994-1996 Mazda MX-3, upstream; 1995-1996 Kia Sephia, upstream; and 1996 Kia Sephia, downstream. The Spectra OS5381 is also a fitment-based replacement for drivers searching for a Mazda Protege oxygen sensor, Kia Sephia upstream oxygen sensor, or Mazda MX-3 upstream O2 sensor. Use part number OS5381 when matching the correct emission control sensor for these vehicles.

What It Helps Address

• Check engine light related to oxygen sensor performance
• Incorrect air-fuel ratio feedback to the engine control system
• Reduced emissions control efficiency
• Rough idle or drivability concerns tied to sensor signal issues
• Failed emissions inspection caused by a worn sensor

Installation Notes and Tips

Confirm the vehicle year, make, model, and sensor position before ordering. This part number OS5381 is listed for both upstream and downstream applications depending on the vehicle, so match the original sensor location exactly. Inspect the connector and harness routing before installation to ensure proper fitment on Mazda Protege and Kia Sephia applications.

Quality Assurance

Spectra Premium states that its oxygen sensors are engineered and manufactured with quality control processes intended to meet or exceed the performance of the original equipment they replace.