The service life of the exhaust system as a whole depends on the operating conditions of the vehicle. With frequent short trips, the deposition of condensate and aggressive substances inside the system increases significantly, which can lead to through corrosion from the inside. Long trips when the engine reaches operating temperature and favorable conditions for the combustion of the air-fuel mixture reduce the corrosive components in the exhaust gas. In addition, solid particles deposited on the inner walls of the system burn out at a high operating temperature. External corrosion occurs under the action of water and salts. A loose engine mount leads to increased engine vibrations, which are transmitted to the fixed connections of both exhaust pipes and further to the entire system.
Therefore, from time to time, in order to prevent possible serious malfunctions, it is necessary to inspect the exhaust system as follows:
- check the threaded connections and fasteners of the exhaust manifold, but if loose fasteners are found, do not overtighten them;
- check rubber bearings for possible breaks, cracks and other damage, replace if found;
- with the engine running, cover the exhaust pipe with a rag. If the engine stops, then the exhaust system is tight. On the contrary, a hissing sound will indicate the place of a possible depressurization;
- if the exhaust has a dull sound, it will soon be necessary to replace the muffler.
The catalytic converter is installed at the front of the exhaust system. Inside it, as a rule, has a fine-mesh structure made of metal or ceramic, through which the exhaust gases pass. The cells are covered with platinum or other similar metal, which reacts and neutralizes harmful substances. A lambda probe is installed in the converter, which detects the content of carbon monoxide in the exhaust gas and transmits this information to the fuel injection system controller. Electronics reacts to this by changing the composition of the mixture.
Removal and installation are not too difficult. You need to pay attention to the following points:
- disconnect the exhaust manifold mount as described above;
- fasten the thermal protection screen with clips;
- unsatisfactory looking rubber suspensions are best replaced.
The gasket between the exhaust manifold double pipe and the catalytic converter must always be replaced when removed.
When screwing the connections of the pipes of the system, it is necessary to fit them tightly to each other. Do not overtighten fastening nuts.
On the 2.9l engine, the exhaust system also includes a turbocharger, an aftercooler and an exhaust gas recirculation system (AGR). These elements are described below.