Best High Flow Catalytic Converters In 2021 Review — Top 9 Products

The catalytic converters are an essential part of any vehicle. In a time where there is growing concern about population, green gas effect, global warming and depletion of the ozone layer, people are always advised and encouraged to reduce the emissions, smoke, pollutants and other harmful compounds. Car manufacturers have also not been left behind, considering cars do contribute to pollution. It has become mandatory for the car to be fitted with a catalytic converter. A device aims to reduce the emissions leaving the car exhaust system and entering the atmosphere. Many governments and states have made t mandatory door cars to not only have the device fitted but also to go for a regular emissions test. Lately, we are starting to hear about the best high flow catalytic converters. What are they and how beneficial are they?

Normality the emission device seeks to reduce the pollutants and emissions leaving the car. However, it does restrict the easy flow of exhaust fumes. What this means is that there will be increased backpressure, and the car’s performance will be undermined. To perform at its peak, the vehicle needs to have minimal restrictions. However, with strict regulations and a desire to improve performance, many people find themselves at a dilemma. Fortunately, the high flow catalytic converter was invented. It restricts the release of toxic emissions but doesn’t affect the flow. This makes the car perform better. The following are the best high flow catalytic converters in the market.

The Top 9 Best High Flow Catalytic Converters

Last update on 2021-10-21 at 06:11 / Affiliate links / Images from Amazon Product Advertising API

#1. Direct-Fit Stainless Steel High Flow Exhaust Catalytic Converter

Catalytic Converter for 2007-2013 Nissan Altima 2.5L | Direct-Fit Stainless Steel High Flow Exhaust

  Get it now on

This high flow cat is perfect for different Nissan models, more specifically, the 2007p-2013 Nissan Altima with the 2.5-liter engine. It will replace the stock units that come with the car as well as modified systems. It is vehicle specific and should fit perfectly. Like other top units, it is also made from stainless steel. Therefore, you don’t expect it to corrode or rust. It is a heavy-duty unit, which handles different temperatures, loads, emissions, and more. The small design improves the space and makes fitting much easier.

It will ensure the emissions are controlled to prevent polluting the environment or the car failing the emission tests. Since it is a high flow unit, it will also give a performance boost. Gases and air will flow through with minimal restriction. This is why you will notice a slight growl after the install. This is mostly experienced at high speeds. It features good design and insulation and has good shock absorption. There’s no doubt that this product is the best High Flow Catalytic Converter.

  • High quality and durable piece
  • It is built using premium stainless steel metal
  • Fits on the exhaust system well without requiring any modification
  • Meets EPA and other emission standards
  • Specifically designed for the said Nissan vehicle and not other types

Our Verdict

This unit will fit perfectly on the recommended Nissan models. It is a high-quality piece and is built from durable materials. It put-up with the high load, extreme temperature, vibrations, emission, carbon and much more quite well. Installing it on the engine is straightforward, and it maintains a tight fit. It will work perfectly and was not interfering with performance or computer management.

#2. Universal Inlet/Outlet Catalytic Converter With O2 Nut

2.5 Inlet:Outlet Catalytic Converter w:O2 Nut Universal-Fit Stainless Steel High Flow CAT

  Get it now on

Fitting the right catalytic converter is one of the best approaches to minimize emissions. You can go a step further and fit a high flow unit, which is less restrictive and allows the gases to flow out much faster and more efficiently. This keeps the performance better and improves the car’s performance. Coming from AUTOSAVER88, this unit will improve the performance of your car. It is very solid and is built from stainless steel. Chances or rust and corrosion are unlikely. It will maintain its shape and good functionality even under extreme heat and pressure.

The shell and the internal ceramic element work together to keep the emissions low. It has a decent diameter and fits on the exhaust system easily. You simply need to remove the current one and replace it with this one. This is a simple process and does not take too much time. It keeps the emissions low, improves engine performance and efficiency. It’s OBDII compliant and has been certified by the EPA.

  • Easy to install on most exhaust systems
  • Compatible with many vehicles
  • High quality and well-priced
  • Improves engine performance and efficiency
  • The sound may have a bit of growl especially at high speed

Our Verdict

This catalytic converter will improve the chances of the vehicle passing the emission tests. It’s also a good replacement for a stock unit that is failing or has failed. Fitting it is simple and takes minimal time. It is a stainless steel unit, which will endure the high temperature, high load, stress, and vibrations well.

#3. Inlet/Outlet Universal Fit Stainless Steel High Flow Exhaust Converter

3 Inch Inlet:Outlet Catalytic Converter - Universal Fit Stainless Steel High Flow Exhaust Converter

  Get it now on

Are you preparing for an emission test or are having issues with the existing one? It is possibly the right time you replaced the catalytic converter. You don’t need to spend lots of moony on a good quality piece. The AUTOSAVER88 -3-inch unit is a popular choice that should suit different vehicles. It comes in a basic design for easy installation. It is constructed from high -quality stainless steel and will not easily corrode, stain or rust. Also, it tolerates the varying temperatures, high heat, and high load quite well. This will work many kinds of vehicles including SUVs, light trucks, minivans, and cars.

Although it looks simple, it is a high-quality piece that will deliver a good performance. It supports a high flow rate, which improves performance. It also keeps the emissions within the recommended levels. This comes from a reputable firm, and you can be more certain it will be reliable and effective. It is compliant with Environmental Protection Agency (EPA) regulations and will help to minimize releasing pollutants to the environment. Once you fit the device, it will serve you for a long time.

  • The installation process is straightforward
  • It is suitable for many types of vehicles
  • It’s made from premium stainless steel
  • Resistant to corrosion and rust
  • Inlet/outlet may be a little large of some pipes

Our Verdict

This device handles the operations well. The stainless steel construction ensures the high temperatures, vibrations, dirt, carbon, fumes and much more. It fits on many vehicles and comes in a simple and basic design. Once installed, it will stay intact for many years to come.

#4. Inlet/Outlet Universal Stainless Steel Catalytic Converter High Flow EPA Approved

2.5 Inlet:Outlet Universal Catalytic Converter High Flow Stainless Steel EPA Approved

  Get it now on

Your search for the best high flow catalytic converter will end after you get this piece from AUTOSAVER88. The universal device fit most cars on the road. It’s most suitable for the earlier model, which did not have any form of a sensor on the catalytic converter. Nevertheless, some consumers say that it still works okay with some newer models. It comprises an inlet and outlet, both measuring 2.5 inches in diameter. This means it should fit in the normal exhaust pipe since it also measures 2.5 inches in diameter.

The device is heavy-duty. It will not have issues dealing with the high temperature, load, road vibrations, environmental factors and much more. It is a durable piece and is effective in minimizing emissions. This pack comes with 2 pieces, and you can save one for later or even give it out as a gift to somebody else.

  • Compatible with many types of vehicles
  • High quality and competitively priced
  • Installation is simple and easy
  • It is made from heavy-duty stainless steel
  • May not work with some late car models

Our Verdict

This catalytic converter ranks as among the best in the market. It is also praised for being simple and easy to install. It works in many vehicles, both early as well as newer ones. The unit is tough and won’t crumble under the heat or pressure easily. The sturdy materials also put up with the heat and vibrations quite well.

#5. Universal Inlet/Outlet Stainless Steel High Flow Converter (EPA Compliant)

Universal 2.25 Inlet:Outlet Catalytic Converter with O2 Nut Stainless Steel High Flow Converter (EPA Compliant)

  Get it now on

This is among the newest high flow catalytic converters you will get in the market. It’s more advanced than most existing types on the market. It will boost performance and efficiency. It’s designed to deliver high performance and exceed OE quality. This also happens without sacrificing flow rate or affecting the Emissions. It is a standard unit with a 2.25- inch outlet and inlet. The accessory will bolt on the most vehicle exhaust pipe white well and without any alteration. It also blends nicely with the surrounding and will not look odd. This is because of its good dimension of 13 inches in length.

It is made of heavy-duty stainless steel and will handle the high load, high temperatures and heat from the exhaust. The ceramic substrates not only deliver decent performance but also ensure the emissions are kept to a minimum. It’s EPA certified, and you are more certain of keeping the emissions minimal. It is also OBDII compliant and will work with later car models as well.

  • Very easy to install and good performance
  • Small compact and space efficient
  • EPA certified and OBDII Compliant
  • Heavy-duty and made from tough stainless steel
  • May not work with some car models

Our Verdict

This high flow catalytic converter comes in a universal styling. It has a 2.5-inch inlet and outlet and should fit on a wide array of cars, both older and newer models. It is a heavy-duty piece and will last a long time. The unit handles the high load and temperature quite well. Installation is a breeze and takes a short time.

#6. Inlet/Outlet Universal Catalytic Converter

Flowmaster 2230125 223 Series 2.5 Inlet:Outlet Universal Catalytic Converter

  Get it now on
  • By: Flowmaster

Symbolic with its brand name, the Flowmaster 2230125 catalytic converter with improving the flow of gases in the exhaust system. While the traditional or standard types focus more on emission, this one focuses on both emission control and good performance. The unit has an effective honeycomb mesh that allows the gases to t escapes from the system freely and in a much faster manner. At the same time, the active compounds in the unit filter out harmful compounds that come from the combustion process. It deactivates them and stops them before they are released into the atmosphere. The gadget will, therefore, limit emissions to a high degree but also improve the performance. You will feel a difference after the installation.

It’s made from stainless steel to handle the high performance, the heat, different temperature, moisture, oils, fuel and much more. The unit will fit on standard exhaust systems and has an inlet and outlet diameter of 2.5 inches. It has incredible flow characteristics and will not undermine the performance of the engine. It’s a universal piece and will work with most vehicles.

  • Excellent performance
  • Easy installation and works great
  • Great value for money
  • Simple design and durable
  • May not be reliable with a catalytic converter that comes with a sensor

Our Verdict

With this unit, you will experience an improvement in vehicle performance. The gases will flow out smoothly, and the car should be more responsive. Despite all this, it will not increase the emissions. The universal unit fits nicely on most exhaust systems since it has an inlet and outlet of 2.5 inches. It’s well made, feels solid and also lasts a long time.

#7. Stainless Steel High Flow Exhaust Manifold (EPA Compliant)

Catalytic Converter for 2002-2006 Nissan Altima:Sentra 2.5L | Direct-Fit

  Get it now on

Do you own a Nissan Sentry or Nissan Ultima with a 2.5-liter engine? Well, if you do, then this catalytic converter is just what you and your car needs. It’s fit for the model years 2002-2006. It comes ready to install and doesn’t need any modification or cutting pipes. You simply remove the current one and then bolt this one. It’s that simple. You can even do it yourself if you have the confidence. It should take you less than 30 minutes to complete the process. Once fitted, you will realize a change in performance for the better. This is because it is a high flow unit. It allows gases and air to pass through more freely. This improves performance as well as the efficiency of the engine.

The unit is made from tough stainless steel and will handle the heat, high temperature, carbon, fuel, and other things quite well. It will last for many years and will maintain good performance. And considering its EPA compliant, you should not worry about failing the MOT or emission tests.

  • High quality and long-lasting
  • Well-made and easy to install
  • Doesn’t require any alteration or modification
  • Improves performance without affecting emissions
  • Not designed for vehicles other than Nissan Sentry and Altima

Our Verdict

This is a good unit for Nissan Altima and Sentry. It comes ready to install and should fit into the existing system easy. It’s made from heavy-duty steel and handles the high temperature well. In addition, since its stainless steel, it is more resistant to corrosion and rust. Although it increases the performance e and efficiency, it does not have any negative effects on the emission.

#8. Universal Stainless Steel Catalytic Converter High Flow

Pair 2.5 Universal Spun Catalytic Converter High Flow Stainless Steel

  Get it now on
  • By: Colt Exhaust

Colt exhaust did go out of their way to come up with this catalytic converter. It is a high flow unit, which will reduce the backpressure and improve the free flow of gases. It almost works like a through pipe, only that it has fewer emissions and is also not as noisy. A closer look reveals that it relies on a superior honeycomb unit, which is less restrictive to the flow of gases. However, it will stop the harmful compounds and pollutants from escaping into the atmosphere. It is a universal piece and should work with a good number of vehicles. It measures 11 inches in length, and the width is about 4 inches. This helps it to take-up as little space as possible. This also makes it a good option for a vehicle with limited spaces underneath.

The versatile unit has an inlet and outlet diameter of 2.5 inches. This is what most stock or standard exhaust pipes measures. In shorts, it will fit on most cars without any modification. And from what previous and current consumers are saying, it fits perfectly. All you need is to set it then weld it, a simple process s that should take a short time.

  • High flow and improves the performance
  • Compact, small and fits nicely on most systems
  • Compatible with a range of car models
  • Made from sturdy and durable materials
  • May not work with some vehicle

Our Verdict

If the best high flow catalytic converter is what you want, then this piece should just be right. It’s simple and comes in a universal size. It fits perfectly on the standard exhaust and does not take you lots of space. It is less restrictive but still doesn’t allow emissions to pass through.

#9. High Flow Catalytic Converter

SLP M31040 High Flow Catalytic Converter - Pair

  Get it now on
  • By: SLP Performance Parts

The SLP M31040 catalytic converter targets users who want to upgrade their existing unit to a more reliable and less restrictive unit. It bolts onto the stock or modified exhaust system without any issues. This is because it is versatile and does not take up too much space. You simply need to remove the existing one and then fit this one. It should work with most systems well and won’t cause any performance issues. In fact, you will experience a boost in performance since it has minimal backpressure and also allows air and gases to flow out freely.

It is made from steel and should handle the high temperature and heat thoroughly. The metal also tolerates stones, chips, vibrations, the weather, and other things, It measures just 12 inches long and is 5 inches in width. And with an inlet and outlet diameter of 2.5 inches, it will work with the majority of the cars. This pack contains 2 pieces, and they all are high flow units. You also get simple instructions on how to go about with the installation. The process is simple and takes minimal time and effort.

  • A high-performance unit
  • Easy to install
  • Works with most car exhaust systems
  • High quality and made from tough steel
  • May increase the exhaust sound slightly

Our Verdict

This is indeed a good pair of high flow catalytic converters. They look the same and are easy to install. The nice size and diameter work okay with most vehicle exhaust systems found in cars. Installing the piece is easy and simple. You also will experience an increase in performance without increasing emissions.

Best High Flow Catalytic Converters Buying Guide

With so many choices of high flow catalytic converters to choose from, picking the best one can be quite challenging. You will be able to make decision faster if you know what to look for in high flow catalytic converters. This buying guide is here to bring you just that, so let’s find out with us below together.


The perfect high flow catalytic converters should be the one that you can install on most exhaust systems. That way, you won’t have to spend so much time trying to find the right one for certain vehicles at all. If it is compatible with most vehicles, it also makes it easy to install and use as well. This part is very important, so do not overlook it.


This is one of the best parts to consider because durability always matter. We are talking about its ability to perform on a daily basis long term so that you won’t waste your money. Durability also refers to its resistance to corrosion and rust as well. That allows for a long lasting durability and quality that works for your vehicles for years. The best part is that you know it works great once it is durable which is a total plus. It can a little bit pricey, but it is worth the price as long as it is durable.


Some of the best high flow catalytic converters come with very easy process of installation. That makes it extra easy for you to get things done by yourself which is simply convenient. Many of them offers instructions that you can easily follow so that you can install it right away. While some others features the easy installation design so that you can also do it on your own. The great part is that if you know how to install it, you also know how to replace it as well. It somehow teaches you a new basic skill, so it is a win-win.


The quality of the material reflects the performance and overall quality of the high flow cat con that you use. Stainless steel is a common and durable material that you can trust for long term use. You hit jackpot if you find the ones that are made from heavy duty stainless steel because it is tougher. Bear in mind that the better the material, the longer it will last so don’t forget to check this part.


The purpose of the high flow catalytic converters is to regulate the exhaust. Most cat cons do its job very well, but some come with flaws; and that is the noise. The best high flow catalytic converters should never make too much noise especially at high speed at all. So the option that you go for should be the ones that work quietly even after long term use. If you notice the growling noise or any similar kinds, you really should replace that one. The right option operates smoothly and silently, and that is the cat con that you should have.


Like any other good citizen and environment lover, you desire to ensure the environments are cleaner, greener, and there is minimal population. This is why you observe all laid out rules and regulations such as ensuring the car has a catalytic converter. However, you still want the car to perform at its optimum. You want fast takeoff, reaching the top speed faster, and also an increase in power and torque. To suit your needs and still keep emissions at a minimum, you can rely on a high flow catalytic converter. This s device gives you the best of both worlds. It minimizes emissions while maximizing performance.

You will find many types in the market, and you must go for the one that suits your cars. In the above read, we have reviewed the best high flow catalytic converters. It took us quite some time and effort to single them out. They are reliable, effective, efficient, easy to install, durable, and also boost performance. Besides, they comply with most regulations. We believe that you will find something that works with your car.

Leave a Comment