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/InstallationFront Body Control Module (Fbcm)
Outline
Located at the front of the vehicle, the front body control module (FBCM)
performs numerous system controls for functions at the front of the vehicle.
Function
The front body control module (FBCM) controls the system based on the input/output
signals.
The fu ...
How the SRS Air Bags Work
Your Mazda is equipped with the following types of SRS air bags. SRS air bags
are designed to work together with the seat belts to help to reduce injuries during
an accident.
The SRS air bags are designed to provide further protection for passengers in
addition to the seat belt functions. Be ...
Speaker [Without Bose®]
Purpose
Converts the audio signal from the audio unit to sound.
Function
Full-range speakers, which can output wide-range sound from low to high frequency,
have been adopted.
Specification
Item
Front door speaker
Rear speaker ...