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/InstallationWheel Hub Component Removal/Installation [Awd]
CAUTION:
Performing the following procedures without first removing the ABS wheel-speed
sensor may possibly cause an open circuit in the wiring harness if it is pulled
by mistake. Before performing the following procedures, disconnect the ABS wheel-speed
sensor connector (body side) ...
Dynamic Stability Control (DSC)
Outline
Electrical brake assist control has been adopted, improving safety.
The DSC HU/CM, integrating both the hydraulic unit (HU) and control module
(CM), has been adopted, resulting in a size and weight reduction.
An enhanced malfunction diagnosis system, used with the M ...
High Pressure Fuel Pump Control
Outline
Changes the fuel pressure applied to the fuel injector according to engine
operation conditions to improve engine output and startability.
The PCM determines the fuel pressure value corresponding to the engine operation
conditions based on the each input signal, and driv ...