High Flow Catalytic Converter Reviews: Spun, Metallic & More
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High Flow Catalytic Converter Reviews

What’s the Best Hi-Flow Cat?

Flowmaster 223 Series Catalytic Converter
Flowmaster 223 Series Catalytic ConverterPaceSetter Hi-Flow Catalytic ConverterEastern Bullet Cat
400 cpsi400 cpsi200 cpsi
2.25" IN / 2.25" OUT2" IN / 2" OUT2.25" IN / 2.25" OUT
2.5" IN / 2.5" OUT2.25" IN / 2.25" OUT2.5" IN / 2.5" OUT
3" IN / 3" OUT2.5" IN / 2.5" OUT3" IN / 3" OUT
3" IN / 3" OUT

Flowmaster 223 Series Catalytic Converter

Flowmaster 223 Series Catalytic Converter

A high flow catalytic converter can be a simple way to improve the performance of your car or truck without increasing your emissions output.

It’s no secret that we are living in the most environmentally conscious period of our lifetimes. That’s great for the planet and our future. However, car enthusiasts have to find new ways to improve their horsepower and still pass emission tests each year.

We’ve assembled a list of the best high flow cats that will help boost your horsepower without breaking the bank – or the law.

Best High Flow Cat: Flowmaster 223 Series Universal Catalytic Converter

Flowmaster 223 Series Universal Catalytic Converter

Our pick for the best high flow cat is the Flowmaster 223 Series universal catalytic converter. These high quality catalytic converters are manufactured in the USA, and feature stainless steel outer shell construction for maximum durability. The internal substrate material and precious metal loading have been carefully engineered for maximum efficiency and to avoid “MIL” code issues that are common with lower quality converters.

Universal catalytic converters require welding or fabrication and should be installed by qualified technicians.

Why choose the Flowmaster universal catalytic converter?

  • Excellent flow characteristics
  • Engineered to keep the “MIL” light off
  • Available for a wide variety of applications
  • Stainless steel construction
  • This item is not for sale in California/Non CARB compliant

Flowmaster 49-state universal catalytic converters are designed to meet federal EPA emission requirements on a wide variety of applications. Flowmaster 49-state converters are not legal for sale or use on vehicles licensed or operated in the state of California.

High flow catalytic converters are available with metallic or ceramic inserts. The Flowmaster 223 is a 3-way converter with a ceramic substrate. It is designed to be used on vehicles with an engine size up to 5.9 L and a maximum gross weight of 5,500 lbs.

Benefits of High Flow Catalytic Converters

Why do we need catalytic converters in the first place? A catalytic converter is a device that reduces and controls vehicle emissions. It does so by converting toxic pollutants in exhaust gas to less toxic pollutants via a catalyst.

The main job of a catalytic converter is to convert carbon monoxide into carbon dioxide and water.

The catalysts are usually a mixture of platinum, palladium, rhodium, and gold. These are very precious metals and are valuable in large quantities – that’s why catalytic converter theft is so common.

So why are stock catalytic converters so inefficient? Inside the converter is an intricate honeycomb structure covered with the catalyst material. The added air resistance slows down the exhaust gas and creates additional backpressure.

One way to improve your car’s performance is to remove any obstacles the exhaust gas encounters as it travels from the exhaust manifold to the exhaust tips. A high flow catalytic converter is designed to have less resistance than a stock version while still meeting national emission standards.

  • Gain more horsepower at higher RPMs
  • More torque at lower RPMs
  • Meets national emission requirements

If you live in California you will need to be careful about upgrading to a high flow catalytic converter. The California Air Resources Board (CARB) has strict requirements on the types of catalytic converters that meet their standards. Most aftermarket converters are designed to meet federal emissions standards. However, they rarely meet California standards. You can learn more about these policies on the CARB website at http://www.arb.ca.gov/homepage.htm