What is a muffler?
A muffler is the final part of the exhaust system that serves to muffle the sound. Inside the muffler is a system of tubes and chambers that are designed to reflect the sound waves from the motor, cancelling out any noise.
Different types of mufflers cancel out different amounts of sound. Some allowing more noise to come out as a result.
(Number 1. on the diagram)
What is a resonator?
The resonator is a smaller sound reduction part of the exhaust system. Inside the resonator is a single chamber that sound waves are sent through. These waves bounce off the inside of the chamber and cancel each other out.
Many people will do a resonator delete where they will take out the resonator completely, having a straight pipe welded in it’s place. This causes the noise from the motor to be amplified, making the car louder.
(Number 2. on the diagram)
What is a catalytic converter?
The purpose of the catalytic converter is to convert harmful pollutants coming from the motor, to less harmful emissions before they leave the car’s exhaust system. Taking out the catalytic converter reduces the airflow restriction of your exhaust. The gasses must exit the exhaust in order for a vacuum to be created and fresh air to flow in the intake side of the system.
Different states have different laws on emissions. Taking out the catalytic converter could result in failing emissions testing. Check your local laws if you are thinking about removing it.
(Number 4. on the diagram)
What is an 02 sensor?
The purpose of the 02 sensor is to monitor how much unburned oxygen is in the exhaust as the exhaust exits the engine. Monitoring oxygen levels in the exhaust is a way of gauging the fuel mixture. It tells the computer if the fuel mixture is burning rich (less oxygen) or lean (more oxygen).
(Number 5. on the diagram)
What is a downpipe?
The downpipe is a section of the exhaust that comes directly off headers or exhaust manifold connecting it to the catalytic converter. However on a car that has a turbo, the downpipe comes directly off of the turbo. “Open downpipe” means that the downpipe is not connected to the rest of the exhaust system. A “full exhaust” is when the downpipe is connected to the rest of the exhaust system.
A downpipe can give your car a significant power increase if you have a turbo because the turbo is essentially a pump, it’s important for the pipes entering and exiting the turbo to have unrestricted airflow.
Downpipe comes “catted” and “non cated or cattless” meaning it either comes with a catalytic converter or it does not.
(Number 6. on the diagram)
What is a cat-back exhaust?
A cat-back exhaust is an exhaust system that is installed behind or after the catalytic converter. This type of system replaces the stock or factory muffler and resonator and piping system with an aftermarket one. A performance cat-back allows for more performance by increasing the diameter of the exhaust, which helps increase the power and sound.
(Number 3. on the diagram)
What is a turbo-back exhaust?
A turbo-back exhaust system is a system that not only replaces the muffler and resonator with an aftermarket one but comes with a new downpipe and catalytic convertor as well. So it is essentially a downpipe and a cat-back exhaust all in one.