Fig. 2.75. Exhaust system: 1 - smooth muffler; 2 - rear oxygen concentration sensor, 54 Nm; 3 - central exhaust pipe; 4 - catalytic converter; 5 - front oxygen concentration sensor, 54 Nm; 6 - exhaust inlet pipe; 7 - gasket; 8 - rubber suspension; 9 - gasket; 10 - bracket; 11 - rubber suspension; 12 - rubber suspension; 13 - exhaust pipe bracket
The exhaust system consists of three main parts. The exhaust system ensures the removal of exhaust gases into the atmosphere, a decrease in the concentration of pollutants, and a reduction in engine noise to the required level with minimal loss of engine power. In order for the exhaust system to perform its functions, it must be in good condition. The condition of the exhaust system also affects engine power and fuel consumption.
Mufflers are designed to smooth out pulsations in the exhaust gas flow and reduce noise levels.
Heat shields are installed to protect the vehicle and the environment from high temperatures generated by the operation of the catalytic converter and the passage of exhaust gases.
The exhaust system is attached to the bottom of the car using elastic elements to reduce vibration from the passage of exhaust gases.
Exhaust leaks in the exhaust system are usually caused by damaged gaskets and leaky pipe connections or damage to the mufflers from impacts while driving. Exhaust leaks result in increased noise and vibration from the contact of exhaust system components with the vehicle body.
Before removing or disassembling exhaust system components, soak the bolts and nuts securing the exhaust system components with a fluid that loosens the connections. Wait 5 minutes for the fluid to penetrate the threaded connection.
After working on the exhaust system, move the exhaust system of the car to the sides, check that it does not touch the car body. Otherwise, replace the rubber hangers of the exhaust system.
Notes.
When aligning and tensioning exhaust system components, always start from the front of the vehicle.
Apply a special anti-stick compound consisting of finely dispersed particles of graphite and glass to the threads of the new oxygen concentration sensor. When the engine is running, the graphite burns off, but the glass layer will remain in place, which will subsequently make it easier to unscrew the sensor from the exhaust pipe. If the sensor was removed, be sure to apply an anti-stick compound to its threads before reinstalling it.
The oxygen sensor is connected to the connector by a flexible wire. This flexible wire must not be disconnected from the sensor. Damage to or removal of the flexible wire may adversely affect the operation of the oxygen sensor. Do not drop or strike the oxygen sensor.