Exhaust System: Description and Operation
Exhaust System
The 6.0L diesel exhaust system consists of the following:
- Turbocharger inlet Y-pipe
- Catalytic converter
- Exhaust downpipe
- Extension pipe (if equipped)
- Muffler and tail pipe assembly
The gasoline exhaust system consists of the following:
- Exhaust Y-pipe
- Catalytic converter (stripped chassis)
- Extension pipe (if equipped)
- Muffler and tail pipe assembly
Exhaust System
The exhaust system provides an exit for exhaust gases and reduces engine noise by passing exhaust gases through the catalytic converters and a muffler assembly. Rubber exhaust hanger isolators attach the exhaust system to the mounting hooks.
Catalytic Converter
The catalytic converter plays a major role in the emission control system. The catalytic converter operates as a gas reactor. Its catalytic function is to speed the heat-producing chemical reaction of components in the exhaust gases in order to reduce air pollutants. The catalyst material inside the catalytic converter consists of a ceramic substrate.
The catalytic converter is designed to provide a long life. No maintenance is necessary for the catalytic converter.
Sound Insulators and Shields
Sound insulators and shields attached to the underbody protect the vehicle from exhaust system heat and should be inspected at regular intervals to make sure they are not dented or out of position. If a sound insulator and shield is damaged or shows evidence of deterioration, a new sound insulator and shield should be installed. The sound insulators and shields for the turbocharger inlet Y-pipe, exhaust Y-pipe, exhaust downpipe, catalytic converter, extension pipe and muffler and tail pipe assembly are installed separately.
Precautions
NOTICE: Do not use leaded fuel in a vehicle equipped with a catalytic converter. In a vehicle that is continually misfueled, the lead in the fuel will be deposited in the catalytic converter and completely blanket the catalyst. Lead reacts with platinum to "poison" the catalyst. Continuous use of leaded fuel can destroy the catalyst and render the catalytic converter useless.
NOTICE: The addition of lead to the catalytic converter can also solidify the catalyst, causing excessive back pressure in the exhaust system and possibly causing engine damage.
NOTICE: Extremely high temperatures (1,100°C [2,012°F] or above) due to misfiring or over-rich fuel/air mixture will cause the ceramic substrate to sinter or burn, destroying the catalytic converter. Do not continue to operate the vehicle if the engine is misfiring, there is a power loss or other unusual operating conditions, such as engine overheating and backfiring.
NOTICE: Do not use oil or grease-based lubricants on the isolators. These lubricants may cause deterioration of the rubber. This can lead to separation of the isolator from the exhaust hanger bracket during vehicle operation.
NOTE: Exhaust fasteners are of a prevailing torque design. Use only new fasteners with the same part number as the original. Torque values must be used as specified during reassembly to make sure of correct retention of exhaust components.
NOTE: The van/wagon exhaust system is used on flex fuel vehicles and some E-350 stripped chassis.
Make sure to follow these precautions when carrying out the procedures.