This is how removing the catalytic converter affects the engine

A catalytic converter is a critical component in the exhaust system, helping clean engine emissions before dumping them into the environment. But does it have anything to do with the engine’s normal operation?

Does removing the catalytic converter affect the engine?

Apart from cleaning the emissions produced by the engine’s combustion chamber, the catalytic converter limits the engine from operating freely.

An engine operating with a catalytic converter in its exhaust system always experiences low horsepower, limited fuel access, poor gas mileage, high heating, and abnormal engine sounding.

Therefore, removing the catalytic converter will affect the engine positively, as it will work freely from what the catalytic converter limits.

What are the Pros of removing a Catalytic Converter?

1. Increased engine horsepower

A catalytic converter is a kind of tank that hosts the emissions and pressure of gasses from the engine. The emitted gasses take some time before being released, and this acts as the backpressure of the engine to release exhausted gasses freely.

Therefore, removing the catalytic converter adds an advantage to the engine as it won’t experience backpressure. Significantly, the engine experiences a maximum potential to perform well and increase its horsepower as nothing anymore acts as a backpressure barrier.

2. Original engine sound

The catalytic converter changes the engine’s sound in most average vehicles, producing a different sound. However, the engine maintains its original sound when the catalytic is removed.

3. Better gas mileage

Catalytic converters often put pressure on the engine because of their constructive design. This means that the engine has to work harder to produce the same energy without a catalytic converter.

Removing the catalytic converter will reduce this burden; hence, the engine can work without straining itself. This implies that you receive a better fuel consumption translating to an overall improvement of the engine’s fuel economy.

4. Relatively lower operating temperature

In the construction process which occurs during exhaust emission, the engine needs to put more pressure to generate enough power.

Heat is generated under the hood, resulting in high operating temperatures. When the catalytic converter is removed, constriction does not occur hence a lower operating temperature.

Moreover, there will be less friction and reduced unit load, minimizing wear and tear on the engine and adjacent parts and reducing maintenance.

What happens if I remove the catalytic converter?

Several things will happen by removing a catalytic converter. First, since the catalytic converter is responsible for burning unburnt exhaust gasses to make them clean before being released into the environment, removing a catalytic converter means that the car’s exhaust gasses will be harmful and unclean.

A car running without a catalytic converter allows exhaust gasses to exit the engine faster than when the converter is available. This reduces the engine backpressure, hence minimizing engine strain; as the car backpressure reduces, the engine horsepower increases, resulting in expelling more gasses, thus improving the fuel economy.

There is also a better gas mileage and lower engine operating temperatures achieved after removing a catalytic converter. On the darker side, a car without a catalytic converter will fail the emission tests and experience low-end torque loss.

Does removing the catalytic converter affect engine performance?

No, removing a catalytic converter won’t affect the engine performance. Instead, it will bring some gains to the less restrictive exhaust, which won’t hurt your engine, provided that you tune it later.

Instead, you will feel some relief on the engine breath due to removing the backpressure that the catalytic converter creates between itself and exhaust manifolds. However, removing the engine converter can increase the risks of damaging parts like oxygen sensors and triggering the check engine light.

What is the overall disadvantage of removing the catalytic converter?

Taking away the catalytic converter from the car gives the privilege of high-performance fuel options at a price. The greatest drawback of removing a catalytic converter from the engine is the increased risk of emission of harmful gasses into the atmosphere, which will act as a pollutant.

Likewise, the car will fail an emission test due to these gasses. Besides that, removing the catalytic converter is illegal in most jurisdictions, as most laws do not allow driving without a catalytic converter. Removing a catalytic converter can also cause a fault code.

Does removing the catalytic converter affect sound?

Removing a car’s catalytic converter affects the sounds that the car produces. Catalytic converter removal often changes the sounds that emanate from the exhaust.

While resonators and mufflers are designed to muffle the engine sound, removing the catalytic converter changes the exhaust sounds, making it even louder and more distinctive.

Does removing the catalytic converter affect gas mileage?

While some may argue that catalytic converters do not affect the gas mileage, it positively affects the gas mileage after their removal. By removing the catalytic converter, there is less strain on the engine due to the restricting effects.

This is because the engine will not have to do double work to produce the same amount of energy. This reduced workload enables the engine to work efficiently, resulting in less fuel consumption and better gas mileage.

How much horsepower does removing a catalytic converter add?

Removing a catalytic converter can add an average of 15 horsepower. However, this depends on the size of the engine; that is, more significant engines gain more horsepower after a decrease in backpressure. If you tune your car after the CAT removal, the car will double the horsepower to 30.


Catalytic converters have a significant role in reducing environmental pollution due to engine exhaust fumes. However, this does not mean that the engine can’t do without it.

Catalytic converters can be safely removed from a car without affecting the functionality and operation of the car’s engine. Instead of hurting the engines, removing this device garners a lot of benefits for the engine, including less strain and increased horsepower. Moreover, the gas mileage of an engine will improve besides reducing the engine’s operating temperatures.

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