Stainless Works MAUCAT Long Tube Headers with High-Flow Catted Lead Pipes Factory Connect

The Stainless Works MAUCAT is a complete long tube header kit engineered for the 2003–2004 Mercury Marauder 4.6L 4V DOHC engine. This bolt-on system pairs high-performance long tube headers with 2-1/2" high-flow metal matrix catalytic converters and catted lead pipes designed to connect directly to the factory exhaust system — no catback modification required.

Constructed from USA-sourced 304L stainless steel and fully TIG-welded with CNC mandrel bends, these headers are built to deliver lasting performance with rust-free durability. The long tube design maximizes exhaust scavenging for measurable gains in both horsepower and mid-range torque.

Key Features:

• 1-5/8" primary tubes for optimized flow velocity across the RPM range
• 3" OD collectors with integrated merge spike for enhanced exhaust scavenging
• 3/8" stainless steel CNC laser-cut flanges port-matched to the cylinder head for optimal flow and maximum performance
• High-flow metal matrix catalytic converters included with 2-1/2" lead pipes
• EGR connection and O2 sensor bungs included for emissions and sensor compatibility
• Factory connect design — mates directly to the stock catback exhaust flange
• Compatible with Stainless Works catback systems as an upgrade option
• Includes header bolts and high-temp RTV for installation
• Optional high-temp black or silver ceramic coating available
• Limited Lifetime Warranty on 304 stainless steel construction
• Proudly designed and manufactured in the USA

The MAUCAT is the definitive exhaust upgrade for the Mercury Marauder platform, delivering a factory-fit installation with race-inspired performance. Note: This product is not California CARB-legal and may not be street-legal in all states — verify local emissions regulations before ordering.