Seal the upper plenum joint and help keep unmetered air out of the intake with the FEL-PRO fuel injection plenum gasket set, part number MS94555. It fits many vehicles, among them the 1986-1995 Ford Mustang, 1991-1993 Ford Thunderbird and 1987-1991 Ford Country Squire with the V8-5.0L engine, and it is a direct-fit replacement for the listed applications. See the "Vehicles it fits" section for the full list.
This premium-grade upper set seals the connection at the fuel injection plenum, which carries metered air into the engine. If a leaking plenum gasket is the cause of a vacuum leak, a hissing sound, rough idle or a lean condition, this set replaces it.
- Built for imperfect sealing surfaces: Engineered and made specifically for the repair environment to help seal surfaces that are less than perfect.
- Sealing technologies: Fel-Pro's exclusive sealing innovations use proprietary materials and unique design features intended to deliver a superior seal for your repair.
- Engineering expertise: Parts are designed, reviewed, validated and approved by Fel-Pro engineers through rigorous research and development.
- Real-world tested: Parts are validated through on-vehicle testing for performance on the road.
The listed applications use one set. Country of origin: United States.
Interchange: AMS4855 · 23593 · 6SZ9H486C · E6SZ9H486C · MS15449 · 748825 · 791059 · MS4182 · 711471800
This part cross-references / interchanges with the following part numbers:
AMS4855, 23593, 6SZ9H486C, E6SZ9H486C, MS15449, 748825, 791059, MS4182, 711471800
Frequently Asked Questions
What does the FEL-PRO MS94555 plenum gasket set do?
It seals the upper fuel injection plenum joint, which carries metered air. This helps keep unmetered air from entering the intake on the listed V8-5.0L applications.
Does it fit a 1986-1995 Ford Mustang with the V8-5.0L engine?
Yes. It is listed for the 1986-1995 Ford Mustang with the V8-5.0L engine, along with other Ford, Lincoln and Mercury models. Check the "Vehicles it fits" section for your exact vehicle.
What are signs the plenum gasket may need replacing?
Possible signs include a vacuum leak, a hissing sound near the intake, rough idle or a lean condition. Diagnose the cause first, because other intake leaks can produce the same symptoms.
Is this an upper or lower plenum set?
This is the upper set for the fuel injection plenum. The listed applications use one set.
What should I know before installing it?
Clean the mating surfaces thoroughly. Follow the vehicle service information for the procedure, the torque values and whether the original fasteners may be reused.
