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/InstallationHeadliner
Purpose/Function
The headliner is equipped with a shock absorbing pad for driver's head protection
during a collision.
Construction
The front and rear side of the headliner is equipped with a shock absorbing
pad with a plastic rib-pad structure.
...
Seat Warmer Switch Removal/Installation
NOTE:
The seat warmer switch are integrated into the climate control unit. (with
full-auto air conditioner system)
The seat warmer switch are integrated into the clock. (with manual air conditioner
system)
For the seat warmer switch removal/installation, refer to the cl ...
Front Combination Light Removal/Installation
WARNING:
Incorrect servicing of the discharge headlights could result in electrical
shock. Before servicing the discharge headlights, always refer to the service
warnings..
NOTE:
Fogging or condensation on the inside of the front combination lights may
occur due to a n ...