Bosch 18105 OE Type Fitment Oxygen Sensor - 4-Wire Heated Direct Fit

The Bosch 18105 is a premium, OE-type direct-fit oxygen sensor engineered for downstream (after-catalytic-converter) applications. As the company that invented the automotive oxygen sensor, Bosch brings decades of manufacturing expertise and OEM-level quality to every replacement sensor it produces.

The oxygen sensor (O2 sensor) plays a critical role in engine management — it continuously monitors the oxygen content of exhaust gases and transmits that data to the engine control unit (ECU). The ECU uses this feedback to optimize the air/fuel mixture in real time, maximizing fuel efficiency, protecting the catalytic converter, and minimizing harmful exhaust emissions. A failing or degraded oxygen sensor can trigger a check engine light, reduce fuel economy, increase emissions, and accelerate catalytic converter wear.

Key Features:

• 4-Wire Heated Design — Built-in heater brings the sensor to operating temperature within seconds, ensuring accurate feedback from cold start and throughout the drive cycle
• Direct OE-Fit Connector — Includes a matched OEM-style connector and wiring harness for plug-and-play installation with no splicing or adapters required
• 8.66-Inch Lead Wire Length — Sized to match original equipment routing for a clean, professional installation
• Anti-Seize Coated Threads — Threads are pre-coated with anti-seize compound right out of the box for easier installation and future serviceability
• Double Laser-Welded Stainless Steel Body — Fully sealed and submersible construction protects the sensor against exhaust heat, moisture, and vibration
• 100% Functionally Tested — Every sensor is tested to Bosch's rigorous OE standards before leaving the factory
• Zirconia Ceramic Sensing Element — The same high-quality ceramic element used in Bosch original equipment sensors for accurate, reliable air/fuel ratio measurement
• Downstream / Post-Catalytic Converter Position — Designed for the rear oxygen sensor location used to monitor catalytic converter efficiency

The Bosch 18105 is sold individually and is a direct replacement for the original equipment oxygen sensor. Cross-reference part numbers include: 234-4456, 250-24909, 25212, 350-34481, OSA61734, OSA61805, and OSA61827.