Purpose, Function
By lengthening the exhaust passage, the transmission of exhaust pressure waves to other cylinders can be delayed, and the amount of gas exhausted from a cylinder and forced back inside the combustion chamber is reduced By reducing the residual gas, the temperature inside the combustion chamber is reduced and the occurrence of knocking even at a high compression ratio is inhibited.
Construction
The exhaust manifold is installed to the rear of the engine. In addition, the catalytic converter (WU-TWC) is integrated (WU-TWC).

When the No.1 cylinder is at the intake stroke, the No.3 cylinder is at the exhaust stroke. By inducing the high temperature gas exhausted from the No.3 cylinder into the No.1 cylinder, the high temperature gas in the No.1 cylinder remains. If the amount of residual gas is high, the temperature in the combustion chamber rises and knocking can easily occur. With the 4-2-1 exhaust system, the transmission of exhaust pressure waves between each cylinder is delayed by the long exhaust pipes.

Exhaust System Removal/InstallationShroud Upper Reinforcement Installation [Panel Replacement]
Symbol Mark
Installation Procedure
1. When installing new parts, measure and adjust the body as necessary to conform
with standard dimensions.
2. Drill holes for the plug welding before installing the new parts.
3. After temporarily installing new parts, make sure the related parts fit p ...
Rear Seat Cushion Trim Removal/Installation
CAUTION:
When removing or putting in the rear seat cushion, contact with the surrounding
areas of the vehicle could cause scratches and damage. When removing or putting
in the rear seat cushion, always use two or more persons to perform the work
and be careful not to scratch or dama ...
Windshield Installation
WARNING:
Using a utility knife with bare hands can cause injury. Always wear gloves
when using a utility knife.
CAUTION:
If a door is opened or closed when all the window glass is closed, the resulting
change in air pressure could cause the sealant to crack preventing the ...