J.C. Whitney JARBM960915 Upstream Heated 4-Wire Oxygen Sensor OEM Replacement

The J.C. Whitney JARBM960915 is a direct-fit, OEM-replacement upstream oxygen sensor designed for select Mitsubishi Montero and Eclipse models. This heated, 4-wire O2 sensor installs in the upstream (pre-catalytic converter) position and plugs directly into the factory wiring harness — no cutting or splicing required.

The upstream oxygen sensor is a critical component in your vehicle's emissions and fuel management system. Mounted in the exhaust manifold ahead of the catalytic converter, it continuously monitors unburned oxygen in the exhaust stream and sends real-time feedback to the engine control unit (ECU). The ECU uses this data to maintain the optimal air-fuel ratio, directly impacting fuel economy, engine performance, and emissions output. A failing upstream O2 sensor commonly triggers check engine codes such as P0131, P0133, or P0135 and can result in poor idle, rough running, and increased fuel consumption.

Key Features:

• Type: Heated oxygen sensor (O2 sensor / lambda sensor)
• Wire Configuration: 4-wire
• Position: Upstream (before catalytic converter, Bank 1 Sensor 1)
• Fit Type: Direct fit — OEM-style connector, correct wire length
• Mounting Style: Threaded installation
• Construction: Durable stainless steel housing
• Replacement Type: OEM-equivalent replacement

This sensor is sold individually and is intended as a quality OEM-style replacement to restore proper closed-loop fuel control, help pass emissions inspections, and clear related diagnostic trouble codes.