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/InstallationRoom Straight Line Dimensions (1) [Dimensions]
Point symbol
Designation
Hole diameter or bolt or nut size mm {in}
A
Front pillar inner datum hole
?7 {0.3}
B
Front pillar inner datum hole
?7 {0.3}
C
...
Tachometer
Purpose
The tachometer notifies the driver of the engine speed.
Function
The instrument cluster controls the tachometer needle based on the engine
speed signal from the PCM and displays the engine speed per minute.
Construction
An analog needle display tachometer ...
Expansion Valve
Purpose
The expansion valve atomizes liquid refrigerant to facilitate cooling of
the evaporator.
Function
The expansion valve reduces the pressure of liquid refrigerant rapidly to
facilitate vaporization of the atomized refrigerant at the evaporator, and adjusts
the refr ...