Mercury O₂ (Oxygen) Sensor
$185.09
Genuine Mercury O₂ (oxygen) sensor for selected MerCruiser EC sterndrive engines. Monitors exhaust oxygen content to optimise fuel delivery, engine performance, fuel economy and emissions control. Suitable for many 4.3L, 4.5L, 5.0L, 5.7L, 6.2L, 8.1L and 8.2L MPI applications.
The Mercury Marine 8M2003959 Oxygen Sensor is a genuine Mercury OEM engine management component designed for selected MerCruiser EC (Emissions Controlled) sterndrive engines. Mounted in the exhaust system, the sensor continuously monitors oxygen levels in the exhaust stream and provides real-time feedback to the engine control module (ECM) to optimise air-fuel ratios for performance, fuel economy and emissions control.
This sensor plays a critical role in closed-loop fuel management systems, allowing the ECM to make precise fuel delivery adjustments based on engine operating conditions. A properly functioning O₂ sensor helps maintain smooth engine performance, efficient fuel consumption and reduced exhaust emissions.
Common symptoms of a failing oxygen sensor include:
- Increased fuel consumption
- Rough idle
- Poor engine performance
- Fault codes or check engine warnings
- Emissions system faults
- Hesitation during acceleration
The 8M2003959 sensor is commonly used on a range of MerCruiser MPI and EC engines, including selected 4.3L, 4.5L, 5.0L, 5.7L, 6.2L, 8.1L and 8.2L MAG applications. It is a 4-wire oxygen sensor designed specifically for marine engine environments.
Manufactured to Mercury Marine specifications, this OEM sensor provides accurate feedback, reliable performance and seamless compatibility with Mercury engine management systems.
