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/InstallationHeated Oxygen Sensor (HO2 S) Heater Control [Skyactiv G 2.0]
Outline
Based on the control of the HO2S heater, a stabilized oxygen concentration
is detected even at low exhaust temperatures, and feedback control of fuel injection
even at cold engine start is made possible for improved cold temperature exhaust
emission performance.
Both ...
Steering Abbreviations
AAS
Active Adaptive Shift
ABS
Antilock Brake System
ABDC
After Bottom Dead Center
ACC
Accessories
AFS
Adaptive Front Lighting System
ALC
...
Propeller Shaft On Vehicle Inspection
Joint Area Excessive Play Inspection
1. Shake the universal joint by hand and verify that there is no excessive play.
2. If there is any excessive play, replace the propeller shaft..
Propeller Shaft Runout Inspection
CAUTION:
Do not rotate the propeller shaft using engine force wh ...