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/InstallationFuel Injector Relay [Skyactiv G 2.0]
Purpose, Function
Supplies power to the PCM for the fuel injector and spill valve control solenoid
valve operation.
Construction
The fuel injector relay is installed in the relay and fuse block.
Operation
When the ignition is switched ON, the battery voltage ...
Start Stop Unit
Purpose
Performs control of several systems based on input/output signals from switches.
Function
The start stop unit controls systems based on the input/output signals.
The functions which are controlled are as follows:
Control Table
Control ...
Control System [Manual Air Conditioner]
Outline
Refrigerant pressure sensor adopted in which refrigerant pressure is changed
into a linear electric signal and precise information is transmitted.
Climate control unit with enlarged operation dials and switches adopted
Structural View
System Wiring Diagram
...