Upgrading your exhaust is a great way to improve performance, enhance engine sound, and even increase fuel efficiency. That’s because a quality aftermarket exhaust is less restrictive than a factory system.

That’s why high-flow catalytic converters (or cats) are a common upgrade alongside an aftermarket exhaust. But if more flow is better, why not remove the cats completely? In this blog, we examine the pros and cons of catalytic converters and how they affect the performance of your vehicle.

Why Upgrade To High Flow Cats?

• Improved performance
• Filter out harmful gases
• Still meet emissions regulations

Mechanical music - or exhaust noise, as your neighbor calls it - is why many of us upgrade our stock exhaust systems. A basic muffler replacement will enhance the sound of your car, but you’ll need a full cat-back system to unleash some extra performance, too.

This is the point where you may be considering a high-flow catalytic converter. These are aftermarket cats designed to maintain emissions compliance while providing improved exhaust flow. In combination with a Thermal R&D exhaust system, this is a great way to get the most out of your aftermarket exhaust.

Why Not Remove The Cats Completely?

• Emissions Compliance Laws
• Exhaust Sound Changes
• Potential performance Issues

A high-flow cat allows exhaust gases to escape faster, reducing exhaust back pressure. The result is more power, improved economy, and a better exhaust note. So why not just remove the cats completely? 

The first reason is that harmful exhaust gases will be released into the atmosphere. Just about every state has strict laws governing the use of catalytic converters. Removing them from road cars is almost always illegal.

Catalytic converters don’t only filter out harmful gases. They keep the exhaust gases hot, which aids combustion and stops corrosive vapor from forming in the exhaust before it is expelled. 

A high-quality aftermarket exhaust, like our Thermal R&D systems, is designed to work with your standard or a high-flow catalytic converter in place. Removing it will change the tone of your exhaust note, and not always for the better.

Also, the oxygen sensors will pick up incorrect readings, leading to the ECU incorrectly adjusting the fuel mixture. This will reduce performance and the vehicle may need its ECU reprogrammed. Your vehicle will also fail an emissions test once the cats are out.

What About Back Pressure?

In older vehicles, cats were an afterthought. They restricted the exhaust gases so much that both performance and economy suffered. The increased back pressure was a big part of the problem.

Catalytic converter technology has advanced greatly in recent years. Instead of just welding in generic cats to meet emissions standards, modern engines are designed to work with them. They no longer severely choke an exhaust system. Or increase back pressure beyond what is required for the engine to operate effectively. But, high-flow cats can still improve performance vs. OE cats.

High Flow Cats Are Sometimes Worth It

Thermal R&D exhausts are designed with Drone Free True Helmholtz Technology. This eliminates the drone you get in most aftermarket systems. And we develop each exhaust to work with a specific make and model. Including the cats. 

We have been perfecting Drone Free True Helmholtz Technology exhausts for 40 years. All our systems are manufactured in the USA from premium materials. And they come with a lifetime warranty.

High flow catalytic converters can be good compromise between improved performance and maintaining emissions compliance. Upgrade your car with one of our premium exhaust systems and you'll likely get the improved performance and sound you crave without the need for high flow cats. Call our team on (661) 591-4142 PST/PDT or get in touch online with any questions - we're happy to help.