Models with carbureted engine 4.2 l
Removing
Exhaust system components
1 - receiving pipe; 2 - nuts; 3 - gasket; 4 - flange; 5 - heat shield; 6 - clamp 7 - bolts; 8 - rubber cushions; 9 - washers; 10 - assembly of the exhaust pipe; 11 - intermediate section with silencer
1. Jack up the car and put it on stands.
Note. Before loosening any exhaust system fasteners, saturate them with a suitable penetrant or rust converter.
2. Give nuts and bolts of fastening of a flange of an exhaust pipe of system to intermediate section with the muffler. Give a nut of a support of an exhaust pipe, remove washers, rubber pillows and a bolt and take an exhaust pipe from under the car.
3. Give nuts and bolts of fastening of intermediate section with the muffler to a reception pipe of system of release of the fulfilled gases.
4. Give the fasteners of the suspension brackets of the intermediate section with a muffler, remove the rubber cushion washers and remove the assembly from under the car.
Note. In case of problems with disconnecting the sections of the system from each other, they can be cut with a hacksaw or pipe cutter and then replaced.
Attention! When giving away "stuck" fasteners, be careful not to damage the floor panels, fuel and brake lines, or chassis wiring.
5. Give nuts of fastening of a reception pipe to a final collector.
6. Give a nut of a back suspension bracket of a reception pipe, remove a washer, rubber pillows, a bolt and take assembly from under the car.
Installation
Installation is in the reverse order.
1. Clean the mating surfaces of all flange connections, be sure to replace the gaskets.
2. First, install all sections of the system on the car, without finally tightening their fasteners.
3. Check the correct location of the components, make sure that they do not come into contact with the bottom of the car and the elements of the chassis and suspension. If necessary, correct the position of the sections.
4. Tighten the fasteners, starting with the flange connection of the front pipe to the exhaust manifold.
5. Start the engine and check the exhaust system for signs of exhaust gas leaks.
6. Eliminate the cause of the identified leaks, then lower the vehicle to the ground.
Models with a 3.0L carburetor engine
The procedures for removing and installing components of the exhaust system are completely similar to those described for 4.2 liter carburetor engines.
1 - heat shield; 2 - bolts; 3 - nuts; 4 - clamp; 5 - gasket; 6 - receiving pipe; 7 - rubber cushions; 8 - washers; 9 - assembly of the exhaust pipe; 10 - bracket; 11 - intermediate section with silencer
Models with 4.2L EFI engine (since 1992 issue.)
The design of the exhaust system of the 4.2L EFI models basically differs little from those shown in the illustrations, with the exception of the installation between the front pipe and the silencer of the catalytic converter.
The catalytic converter is a component of the exhaust gas toxicity reduction system and is a ceramic core placed in a metal casing coated with a layer of platinum, palladium and rhodium. Passing through the converter, hydrocarbon compounds contained in the exhaust gases, nitrogen oxides (NOx) and carbon monoxide (SO) are converted as a result of chemical reactions into carbon dioxide, nitrogen and water.
Under normal conditions, the catalytic converter does not require regular maintenance or replacement. However, it can be damaged or irreversibly contaminated by exposure to excessive exhaust gas temperatures, raw fuel, or leaded fuel (high lead). To prevent accidental filling with leaded fuel, the gas tank of the 4.2L EFI models is equipped with a smaller diameter filler neck, which is also equipped with a spring-loaded trap door. The ceramic core can also be damaged by impacts and strong shocks. When the core is overheated or leaded, its permeability is disturbed, which leads to a decrease in the flow area of the exhaust tract, an increase in the resistance to the release of gases and, thereby, a decrease in the efficiency of the engine.
The engine of a car equipped with a catalytic converter should be filled with oil with a reduced phosphorus content.
To avoid damage to the catalytic converter, the following rules must be observed:
- Do not fill your vehicle with leaded fuel;
- Do not start the car with a dot and do not tow it;
- Try not to allow the engine to idle for a long time;
- Do not drive the vehicle if misfiring occurs;
- Avoid running out of fuel.