DEF Idle Air Control Valve Motor (IAC) Replacement Set of 2 — Direct-Fit 862998/18-7701 with Gaskets

These two DEF Idle Air Control (IAC) valve motors, part numbers 862998 and 18-7701, are direct-fit replacements supplied with gaskets for compatible marine and automotive ECM 555 (2001 and newer) and a range of Alpha/Bravo engines.

If your engine is experiencing rough idle, inconsistent RPM, or you need a reliable service replacement for routine maintenance, these DEF IAC valves provide a straightforward swap. Sold as a pair with replacement gaskets, they match the OE fit for multiple V8 and V6 marine powerplants and several automotive EFI applications, making them a practical spare-parts purchase for boat owners and mechanics.

Which engines and control modules will these IAC valves fit?

These replacement valves are engineered to fit ECM 555 control systems (2001 and later) and a wide set of Alpha and Bravo engine families. They cover several displacement options and both MPI and EFI setups common in marine propulsion.

• Compatible with ECM 555 models from 2001 onward
• Fits Alpha engines: 4.3L, 5.0L, 5.0LX, 5.7L (including Bravo EFI variants)
• Compatible with MAG and MPI engines: 350 MAG, 454 MAG MPI, 502 MAG MPI
• Supports large-displacement MIE/MPI models: 7.4L and 8.2L

How do these valves address idle and throttle issues?

Idle Air Control valves regulate airflow around the throttle plate when the throttle is closed, helping maintain stable idle speed and smooth transitions. Replacing a worn or sticking valve can restore consistent RPM and reduce stalling or surging at idle.

• Restores controlled bypass airflow when the throttle is closed
• Helps correct low, fluctuating, or high idle conditions
• Reduces hunting or surging caused by faulty IAC operation
• Delivered with gaskets for a proper seal during installation

What comes in the package and what should I prepare for installation?

The product is shipped as a set of two DEF Idle Air Control valves with replacement gaskets, ready for direct installation. Basic hand tools and adherence to vehicle or marine service manuals are recommended for a safe and effective swap.

• Includes 2x DEF IAC valve motors (862998 / 18-7701)
• Comes with matching gaskets to ensure proper sealing
• Prepare standard hand tools, torque specs, and a clean mating surface
• Follow ECM-specific programming or adaptation procedures if required

Are these new parts and how do they compare to OEM units?

These DEF valves are brand-new replacement units manufactured to meet fit and function expectations for the referenced numbers. They are intended as direct-fit service parts for mechanics and owners who need reliable replacements without sourcing costly OEM originals.

• New, unused components designed for direct interchange
• Built to match mounting, electrical, and airflow characteristics of OE parts
• Sold as service-replacement pair for convenience and spares

Who is this for: This set is aimed at marine technicians, boat owners, and automotive mechanics maintaining or repairing Alpha/Bravo and MAG/MPI-equipped engines controlled by ECM 555 (2001+). It's ideal for anyone needing a straightforward, cost-effective replacement for aging or failing IAC valves who wants the convenience of a two-piece kit with gaskets included.