Which exhaust valve is right for your car depends on your vehicle's engine, emissions requirements, and driving style. Here are the most popular types of exhaust valves:

The catalytic converter converts hydrocarbons into less harmful pollutants before they leave the exhaust pipe. The "straight-through" valve allows a full flow of air and fuel through the converter, while the "bi-metallic" valve opens and shuts as needed to control pollution levels.

The "dual exhaust" system uses two separate exhaust valves, one for each side of the engine. The "muffler-backpack" valve routes the noise from the back of the engine down to the muffler, while the "header-backpack" valve sends all the noise forward to attract attention.

There are many types of exhaust valves used in cars. Each valve is designed for a specific purpose, such as emissions reduction or power output. The type of valve you choose will depend on your car's engine and configuration. Here is a quick overview of the most common exhaust valves:

Exhaust Valves: 

-Intake Valve (Also known as the Air Intake Valve): This valve opens when the engine starts up to allow air into the engine. It closes once the engine has warmed up and is running at maximum speed. 

-Catalytic Converter: This valve helps reduce emissions by burning pollutants off of the exhaust gas. The catalytic converter converts hydrocarbons (the main component of pollution) into harmless products. 

-Exhaust Gas Recirculation (EGR): This valve allows excess exhaust gas to flow back into the intake manifold. This helps reduce nitrogen oxide emissions and improve fuel economy.