Flowmaster · New
Flowmaster 86-04 Mustang 4.6L/5.0L American Thunder Exhaust Cat-Back System
MPN 817574 · Store SKU flo817574
Supplier stock checked 11/8/2026, 7:13:17 AM UTC. Adding a part does not reserve it.
Request a return within 30 calendar days after delivery. New parts must be unopened and unused.
Shipping & returns ↗This policy does not limit rights required by law.Free standard shipping on eligible parts orders of $100 or more. Oversized and freight items excluded. Fitment, taxes, availability and final totals are confirmed before payment.
Product details
Flowmaster's race-inspired American Thunder® Extreme Cat-back system is designed to mount behind the factory catalytic converters, or most original style aftermarket H-pipes. The turn-down tailpipes drop at the rear of the transmission and eliminates full length tailpipes to maximize the sound level and allow for extra clearance for wide tires and modified suspensions. These systems are mandrel bent for maximum performance and include Super 44 series mufflers. This American Thunder Extreme system delivers a super aggressive interior and exterior tone and is suited to the enthusiast who wants the most aggressive components they can purchase. Like all Flowmaster systems, the benefits include improved throttle response and power. Designed for an easy fit, these systems include all necessary parts and hardware for easy installation. Notes: Fits coupes and convertibles 1986-2004 Ford Mustang GT, LX, & Cobra with 4.6L and 5.0L engines. Fits coupes and convertibles - Aggressive sound Flowmaster American Thunder Cat-back Exhaust System
Manufacturer fitment & guides
Check 817574 against the manufacturer’s application information below.
A manufacturer application guide is not available for this listing. Request the exact application from JuiceBuilt before payment.
Part-specific notes
- Emissions acknowledgement required before purchase.
- California Proposition 65: Y
