Walker 250-21004 Oxygen Sensor - Upstream

OE Oxygen Sensor for Upstream Applications

Walker Products OE 250-21004 is a specific-fit, threaded oxygen sensor built for upstream placement on select Ford, Jeep, and Mercury vehicles. It is engineered to provide the ECU with the feedback needed for fuel control and emissions monitoring, making it a direct replacement choice for older engine management systems.

Compatible With 1981-1986 Jeep Cherokee, 1981-1986 Jeep CJ5, 1981-1986 Jeep CJ7, 1981-1986 Jeep Grand Wagoneer, 1981-1986 Jeep J10, 1981-1986 Jeep Scrambler, 1981-1986 Jeep Wagoneer, 1984-1986 Ford Bronco, and 1984-1986 Ford F-150 applications in upstream positions. Part number 250-21004 is also listed for 1986 Ford Taurus, 1986 Mercury Sable, and 1984-1986 Mercury Topaz upstream service.

• Specific-fit Walker Products OE oxygen sensor
• Upstream sensor placement for engine management feedback
• Non-heated sensor design
• Threaded mounting with 18.0 mm thread diameter
• Female connector with radiused polygon shape
• 13.31 in. wiring harness length and 20-gauge wire
• Overall length: 16.85 in.

Walker Products OE Line Details

Walker Products OE focuses on replacement sensors engineered for the original application, fitment position, and ECU feedback requirements. The 250-21004 follows that approach for vehicles that rely on an upstream oxygen sensor to monitor exhaust content and help the engine control system maintain proper air-fuel operation. If you are servicing a Ford Bronco, Jeep CJ7, or Mercury Topaz with an upstream sensor fault, this part number is built around that exact use case.

What This Oxygen Sensor Helps Address

• Check engine light related to upstream oxygen sensor performance
• Poor fuel economy caused by incorrect air-fuel feedback
• Rough running or inconsistent engine operation
• Elevated exhaust emissions from a failing sensor
• Stored ECU fault codes tied to the affected sensor circuit

Installation Notes

Confirm the vehicle uses an upstream, threaded oxygen sensor before ordering. Inspect the sensor wiring harness and connector for heat damage, abrasion, or corrosion, since damaged wiring can shorten service life and affect signal quality. Verify connector shape, thread diameter, and harness length against the original part before installation.

Quality Assurance

Walker Products has produced engine management and fuel system components since 1946 and operates as an ISO 9001/TS 16949 certified company. The 250-21004 is manufactured as an OE-style replacement for the specified application and position.