Jeep Cherokee (XJ): Description and operation

Exhaust system

DESCRIPTION

The basic exhaust system consists of exhaust manifold( s), exhaust pipe with oxygen sensors, catalytic converter(s), heat shield(s), muffler and tailpipe (Fig. 1) (Fig. 2) (Fig. 3)

Fig. 1 Exhaust Pipe-2.5L

1 - NUT
2 - TRANSMISSION SUPPORT
3 - MINI CATALYTIC CONVERTER
4 - EXHAUST PIPE
5 - EXHAUST MANIFOLD

Fig. 2 Exhaust Pipe-4.0L

1 - NUT
2 - EXHAUST MANIFOLD
3 - TRANSMISSION SUPPORT
4 - EXHAUST PIPE
5 - MINI CATALYTIC CONVERTER
6 - BOLT

БЮ Fig. 3 Exhaust System-Typical

1 - STUD
2 - TAIL PIPE HANGER
3 - CLAMP
4 - ISOLATOR
5 - BOLT
6 - TAIL PIPE HANGER
7 - NUT
8 - MUFFLER
9 - CLAMP
10 - CATALYTIC CONVERTER
11 - HEAT SHIELD

Catalytic converters

DESCRIPTION

California emissions vehicles incorporate two mini catalytic converters into the exhaust system. These catalytic converters are made of stainless steel designed to operate at extremely high temperatures.

The stainless steel catalytic converter body is designed to last the life of the vehicle. Excessive heat can result in bulging or other distortion, but excessive heat will not be the fault of the converter. If unburned fuel enters the converter, overheating may occur. If a converter is heat-damaged, correct the cause of the damage at the same time the converter is replaced. Also, inspect all other components of the exhaust system for heat damage.

Unleaded gasoline must be used to avoid contaminating the catalyst core.

Fig. 4 4.0L Catalytic Converter and O2 Sensor Configuration-(California Emissions only)

1 - O2 SENSOR
2 - O2 SENSOR
3 - O2 SENSOR
4 - O2 SENSOR
5 - O2 SENSOR
6 - O2 SENSOR

Federal emission vehicles use only one catalytic converter, However, California emission vehicles incorporate two mini catalytic converters located after the exhaust manifolds and before the inline catalytic converter (Fig. 4).

Muffler

DESCRIPTION

Both the 2.5L and 4.0L engines use a galvanized steel muffler to control exhaust noise levels and exhaust back pressure.

Fig. 5 Muffler-Typical

1 - MUFFLER

Tailpipe

DESCRIPTION

The tail pipe is also made of galvanized steel.

OPERATION

The tailpipe channels the exhaust out of the muffler and out from under the vehicle to control noise and prevent exhaust gas fumes from entering the passenger compartment.

Fig. 6 Tailpipe-Typical

1 - TAILPIPE