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/InstallationClock Inspection
1. Disconnect the negative battery cable..
2. Remove the following parts:
a. Shift lever knob (MTX).
b. Front console box.
c. Shift panel.
d. Upper panel.
e. Rear console.
f. Side wall.
g. Decoration panel.
h. Front console.
i. Glove compartment.
j. Climate control unit.
3. C ...
Engine SST
1: Mazda SST number
2: Global SST number
Example
1:49 UN20 5072
2:205–072
Holder
1:–
2:AKS042808
Adapter
1: 49 UN20 5072
2: 205–072
Holder
1: 49 B011 105
2: –
...
Master Warning Light
Purpose
The master warning light warns the driver that any of the following malfunctions
is occurring.
Brake switch malfunction
Engine oil solenoid valve malfunction
Automatic configuration malfunction
Function
The instrument cluster i ...