EXHAUST SYSTEM: Let's discuss the exhaust system. As we can see here in the diagram, as the super heated exhaust gases are pushed out of the individual cylinders, they travel through the exhaust manifold down through the exhaust pipe through a muffler or series of mufflers and out the tail pipe at the rear of the car. The exhaust is conserved to take the heat from the engine away from the motor and out to the rear of the car. New cars manufactured after 1970 require a catalytic converter. The catalytic converter is what requires the unleaded gas that you have to buy at the fuel pump. The catalytic converter requires no maintenance but if it becomes clogged, you'll notice a continuing loss of power and the converter may begin to smoke. As the exhaust pipe moves away from the car, it encounters at least one muffler before exiting at the rear of the car. If you notice any holes or excessive noise coming from the muffler or the tailpipe, you'll need to replace them as units. There is no regular maintenance for the exhaust system, but if you do notice abnormal noise or if you smell fumes in the driver's compartment, take it to a qualified muffler shop for immediate inspection. THE EGR VALVE: The EGR valve is an exhaust system emission control device which recycles excessive exhaust gases back to the intake system where it dilutes the air fuel mixture, which lowers the temperature in the combustion chambers resulting in fewer emissions.
