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/InstallationIntermediate Shaft Removal/Installation
WARNING:
The steering column (EPS motor) temperature increases directly after continuous
turning of the steering mechanism which could cause burns if it is touched.
Before performing any servicing, verify that the steering column has cooled
off.
1. Rotate the steering wheel un ...
Theft-Deterrent System
If the theft deterrent system detects an inappropriate entry into the vehicle,
which could result in the vehicle or its contents being stolen, the alarm alerts
the surrounding area of an abnormality by sounding the horn and flashing the hazard
warning lights.
The system will not function unle ...
Rear Window Glass Installation
WARNING:
Using a utility knife with bare hands can cause injury. Always wear gloves
when using a utility knife.
CAUTION:
Proper installation of the glass may be difficult if sealant is cracked or
the glass is pushed out by air pressure when a door is opened/closed with al ...