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/InstallationElectric Variable Valve Timing Actuator Inspection
WARNING:
A hot engine can cause severe burns. Turn off the engine and wait until it
is cool before servicing.
CAUTION:
Do not disassemble the electric variable valve timing actuator because it
is a precision unit.
1. Disconnect the negative battery cable..
2. Remo ...
Body Sealing [Water Proof And Rust Preventive]
Sealant is applied to the parts where the panels meet and to the hemmed parts
of the door panel and hood panel to provide water proofing and rust proofing.
...
Accelerator Pedal, Kickdown Switch [Skyactiv G 2.0]
Purpose, Function
The driver's intentions are transmitted to the PCM via the accelerator pedal.
Kickdown switch (ATX) (Applied VIN (assumed): JM3 KE2*E*D# 148107?)
If the accelerator pedal is depressed carelessly, kickdown control will be
implemented based on the accelera ...