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/InstallationCar Navigation System
Outline
The car-navigation system displays point-of-origin and road guidance maps
via the audio unit display and provides guidance and information to the desired
point of destination.
NOTE:
For the car-navigation system operation, refer to the owner's manual.
...
Shift Point Control (Manual Shift Control) [Fw6 A EL, Fw6 Ax EL]
Outline
The TCM operates the manual shift control when the M position is selected.
If the M position is selected, manual shifting is prioritized according to
the driver’s shift up/shift down operation. However, to assure driving safety
and protect the ATX, minimum automatic sh ...
Driveline/Axle Abbreviations
AAS
Active Adaptive Shift
ABS
Antilock Brake System
ABDC
After Bottom Dead Center
ACC
Accessories
AFS
Adaptive Front Lighting System
ALC
...