Resonator Vs. Catalytic Converter

by Contributing WriterUpdated July 13, 2023
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Notice the check engine light on your dash is lit? The resonator or catalytic converter could be the issue, but what exactly are these car parts? Resonators and catalytic converters are parts that are installed in the exhaust systems of vehicles. When both devices are used properly, they help to reduce emissions and lower the amount of engine noise emitted from an exhaust system. Although they both serve as parts in the exhaust system, a few differences make it possible to tell them apart.

What Does an Exhaust Resonator Do?

A resonator is a chamber on the muffler that is responsible for helping to alleviate some of engine sounds caused by airflow through the vehicle’s exhaust system and out the tailpipe. The resonator is made to produce a sound wave form that cancels out a certain sound frequency in the exhaust pipe. The specific frequency it cancels out depends on the vehicle it is attached to.

What Does a Catalytic Converter Do?

The catalytic converter on a vehicle is used to lower the amount of toxic byproduct emitting from the combustion process of an engine on a vehicle. A catalytic converter is comprised of three different parts. Those parts are the core, the washcoat, and the catalyst. The core is shaped like a honeycomb and is in place to provide extra surface area for the converter. The washcoat makes the converter more efficient by providing a place to store active precious metal deposits. The catalyst is usually made of platinum or palladium. The platinum or palladium strips the nitrogen atom from the air coming out of the exhaust, causing it to form oxygen.

How They're Often Confused

Catalytic converters and resonators are often thought to be the same object, as they are both part of the exhaust system. However, the parts in exhaust systems perform separate tasks. A catalytic converter does not reduce the amount of exhaust noise and a resonator does not reduce the toxic emissions of a vehicle.


A resonator is not required by law to be attached to a vehicle. The resonator is meant to make the noise generated by a vehicle more tolerable, but does not have an impact on the performance of the vehicle. A catalytic converter is required by law. This is because both the national government’s Environmental Protection Agency (EPA) and states have laws regarding the emission of toxic byproducts released from vehicles such as carbon monoxide. If a catalytic converter were to be removed from a vehicle, the vehicle would not pass emissions safety tests.


Removal of the catalytic converter would not increase the performance of a vehicle. However, removing the resonator on a vehicle can boost the horsepower of the vehicle. This is often done in vehicles used for motor sports intended for high performance. Removing the resonator will cause the exhaust sounds to become more audible. This can be tamed by using a tuned muffler, which will lower the volume and pitch of the sound being emitted from the car’s exhaust.

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