A finely tuned engine isn’t just about power—it’s about efficiency, precision, and clean operation. The Quicksilver Exhaust Oxygen Sensor (8M2003959) plays a crucial role in ensuring your MerCruiser sterndrive runs at peak performance by providing real-time exhaust gas data to the engine control module (ECM). This sensor helps regulate the air-fuel mixture, allowing for smoother operation, better fuel efficiency, and lower emissions. A failing O2 sensor can lead to poor combustion, increased fuel consumption, and sluggish throttle response—swapping in a fresh OEM replacement keeps everything running as it should.

Built for Marine Performance:

• Accurate Fuel Adjustment – Continuously monitors exhaust gases to maintain the ideal air-fuel ratio.
• Durable Marine-Grade Design – Engineered to withstand heat, moisture, and corrosion in harsh marine environments.
• Seamless OEM Fit – Designed for MerCruiser 3.0L MPI EC, 4.3L MPI Alpha/Bravo EC, 5.0L MPI Alpha/Bravo EC, 350 MAG MPI Alpha/Bravo EC, and more.

When it comes to keeping an engine efficient, the details matter. A properly functioning oxygen sensor ensures better throttle response, reduced fuel waste, and a longer-lasting engine. If performance is slipping or fuel economy is suffering, replacing a worn sensor with a genuine Quicksilver O2 sensor is an easy way to restore efficiency and keep your sterndrive running strong.