MCATX 4.55" Spun Manifold Insert Converter
4505MS
MCATX Spun Manifold Insert converters deliver OEM-grade emissions performance in a compact, installer-friendly design. Built in the USA with premium materials and proven catalytic chemistry, MCATX converters offer reliable EPA compliance and long-term durability for most popular vehicle applications. This converter is perfect for those hard to install applications that require custom solutions with one end already spun. For difficult vehicles, choose the extra duty converter loadings.
Key Features
-
True EPA-Compliant Performance
OEM-grade washcoat technology ensures clean emissions and consistent catalytic activity. -
Premium Construction
Uses high-quality vermiculite insulation and OEM-sourced substrates for stronger retention, better heat management, and reduced rattling. -
Installer-Friendly Design
Compact body fits tight spaces. -
High Reliability
Backed by over 30 years of converter engineering with some of the lowest warranty claim rates in the industry. -
Broad Compatibility
Designed to cover a wide range of vehicles with fewer SKUs, making selection simple and efficient. -
Made in the USA
Engineered and manufactured domestically for quality, consistency, and peace of mind.
MCATX Spun Manifold Insert converters deliver OEM-grade emissions performance in a compact, installer-friendly design. Built in the USA with premium materials and proven catalytic chemistry, MCATX converters offer reliable EPA compliance and long-term durability for most popular vehicle applications. This converter is perfect for those hard to install applications that require custom solutions with one end already spun. For difficult vehicles, choose the extra duty converter loadings.
Key Features
-
True EPA-Compliant Performance
OEM-grade washcoat technology ensures clean emissions and consistent catalytic activity. -
Premium Construction
Uses high-quality vermiculite insulation and OEM-sourced substrates for stronger retention, better heat management, and reduced rattling. -
Installer-Friendly Design
Compact body fits tight spaces. -
High Reliability
Backed by over 30 years of converter engineering with some of the lowest warranty claim rates in the industry. -
Broad Compatibility
Designed to cover a wide range of vehicles with fewer SKUs, making selection simple and efficient. -
Made in the USA
Engineered and manufactured domestically for quality, consistency, and peace of mind.
MCATX Spun Manifold Insert converters deliver OEM-grade emissions performance in a compact, installer-friendly design. Built in the USA with premium materials and proven catalytic chemistry, MCATX converters offer reliable EPA compliance and long-term durability for most popular vehicle applications. This converter is perfect for those hard to install applications that require custom solutions with one end already spun. For difficult vehicles, choose the extra duty converter loadings.
Key Features
-
True EPA-Compliant Performance
OEM-grade washcoat technology ensures clean emissions and consistent catalytic activity. -
Premium Construction
Uses high-quality vermiculite insulation and OEM-sourced substrates for stronger retention, better heat management, and reduced rattling. -
Installer-Friendly Design
Compact body fits tight spaces. -
High Reliability
Backed by over 30 years of converter engineering with some of the lowest warranty claim rates in the industry. -
Broad Compatibility
Designed to cover a wide range of vehicles with fewer SKUs, making selection simple and efficient. -
Made in the USA
Engineered and manufactured domestically for quality, consistency, and peace of mind.
SHIPPING & RETURNS
Free shipping
Free ground shipping to the lower 48 states. We cannot deliver to P.O. Boxes. Orders usually fulfill in a few business days.
Expedited shipping
Expedited shipping is available at checkout. Miller CAT passes through carrier charges at cost — we do not mark up expedited shipping. Keep in mind:
- Shipping services do not operate on weekends or holidays
- Orders placed after 1:00 PM CST may not ship until the next business day
International orders
Duties and taxes are collected at checkout and paid on your behalf — the price you see is the final price you pay. EU customers have a 14-day right of withdrawal. View our full shipping policy.
Returns
We have a 30-day return window for unused, uninstalled products in original packaging. Returns are subject to a restocking fee of up to 20%. Please verify vehicle compatibility before purchasing — these products are large and expensive to ship, and every return has an environmental cost. View our full return policy.
Warranty Coverage
Emissions Performance Warranty - 25,000 Miles
Our catalytic converters are warranted to meet Federal EPA emissions performance requirements for 25,000 miles from the date of installation, when installed on a properly maintained, EPA-certified vehicle.
Construction & Materials Warranty - 5 Years/50,000 Miles
We warranty the converter’s stainless steel shell, internal substrate, and welds against defects in materials and workmanship for 5 years or 50,000 miles, whichever comes first.
What This Warranty Does NOT Cover
This warranty does not apply to converters damaged or failed due to:
- Improper installation
- Use on non-approved or modified vehicles
- Engine conditions such as misfires, rich/lean fuel mixture, oil or coolant burning
- Physical impact, road debris, or off-road use
- Contaminated fuel or additives
- Any pre-existing mechanical issues that affect emissions
- Labor, diagnostics, shipping, towing, or incidental costs are not covered.
Our MCATX manifold insert converters are engineered to deliver OEM-grade emissions performance in a compact, installer-friendly package. Built in the USA with OEM-sourced substrates and advanced washcoat technology, these converters are designed to meet EPA performance standards on applicable federal-emissions vehicles.
Premium vermiculite insulation improves heat management and substrate retention, reducing rattles and eliminating the need for bulky external heat shields. The compact body and high-quality construction make installation easier in tight or hard-to-reach applications.
We do our best to keep compatibility information up to date. For the most accurate fitment, always confirm your vehicle’s emissions certification (Federal vs. CARB), and match by year, make, model, engine, and emissions family before ordering. These units are EPA-compliant but are not CARB-approved.