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/InstallationSpark Plug Removal/Installation [Skyactiv G 2.0]
CAUTION:
If a spark plug that is not as specified is installed, engine performance
will be deteriorated. Install only the specified spark plug when replacing.
1. Disconnect the negative battery cable..
2. Remove the plug hole plate..
3. Remove the ignition coils..
4. Remove th ...
Electrical System
Electrical Parts
Battery cable
Before disconnecting connectors or removing electrical parts, disconnect
the negative battery cable.
Wiring Harness
To remove the wiring harness from the clip in the engine room, pry up the
hook of the clip using a flathead screwdriver. ...
Remote Handle Lever Removal/Installation
1. Disconnect the negative battery cable..
2. Remove the following parts:
a. Trunk board.
b. Trunk end trim.
c. Rear scuff plate.
d. Trunk side trim.
3. Disconnect the remote cable on the remote handle lever side from the remote
cable on the rear seat side.
4. Remove the remote c ...