1.1 Exhaust SystemThe basic exhaust system components (Fig. 1-1) are an exhaust manifold, front pipe, and muffler with integral tailpipe. All gasoline models have an additional middle muffler, or resonator, and all U.S. models have a catalytic converter. Some Canada cars have a pre-muffler in place of the catalytic converter. On turbo diesel models, the turbocharger is mounted between the exhaust manifold and front pipe.
The exhaust manifold is mounted to the cylinder head and channels exhaust from the four exhaust ports to the front pipe. The manifold is made of cast iron to withstand the extreme heat, vibration, and pressures of combustion. The corrosion-resistant alloy steel front pipe mounts to the exhaust manifold at the top, and to the catalytic converter or pre-muffler at the bottom. On some models, the catalytic converter and the front pipe are one piece. The converter housing is stainless steel. The remainder of the exhaust system is mild steel treated to resist corrosion. The front end of the system is supported by attachment to the exhaust manifold, while the middle and rear mufflers are suspended by six rubber retaining rings or hangers from the underbody of the car. The retaining rings provide positive but non-rigid mounting, allowing expansion and contraction of the system due to changes in temperature and helping to isolate noise and vibration from the body. |