Quicksilver 864856A1 MAP Sensor for MerCruiser GM V6 & V8 EFI Engines 350/377/454/502

The Quicksilver 864856A1 Manifold Absolute Pressure (MAP) Sensor is a genuine OEM replacement sensor engineered for MerCruiser GM V6 and V8 electronic fuel-injected marine engines. The MAP sensor is a critical component of the engine management system, continuously measuring intake manifold pressure and relaying that data to the ECM to optimize fuel delivery, ignition timing, and overall engine performance.

Key Features:

• Genuine OEM Mercury Marine / Quicksilver factory part
• Designed for MerCruiser MCM/MIE GM V6 and V8 EFI engines (350, 377, 454 & 502 CID)
• Built to perform in harsh marine environments including extreme temperatures, vibration, and thermal and mechanical shock
• Provides precise manifold absolute pressure measurements for accurate fuel and ignition control
• Direct OEM replacement — no modifications required
• Backed by Mercury Marine's 1-year factory warranty against defects and workmanship

Cross-Reference Part Numbers:

• Mercury / Quicksilver: 864856A1, 805217A1, 48004, 10-64074, 56214
• Volvo Penta / OMC: 3850396
• Sierra: 18-7684 (S18-7684)

This MAP sensor is a direct-fit, factory-spec replacement that restores proper EFI engine management function, helping maintain peak performance and fuel efficiency in your MerCruiser-powered vessel.