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/InstallationIntake Manifold Vacuum Inspection
1. Disconnect the evaporative hose No.3 (purge solenoid valve side) and install
the vacuum gauge..
2. Verify that the intake air hoses are installed securely.
3. Warm up the engine.
4. Measure the intake manifold vacuum while idling (no load) using the vacuum
gauge.
If not within t ...
Dashboard Disassembly/Assembly
1. Disassemble in the order indicated in the table.
1
Wiring harness
2
Screw A
3
Screw B
4
Dashboard member
5
Screw C
6
Duct No.1
...
Tires
For reasons of proper performance, safety, and better fuel economy, always maintain
recommended tire inflation pressures and stay within the recommended load limits
and weight distribution.
WARNING
Using Different Tire Types:
Driving your vehicle with different types of tires is dangerous. It ...