Exhaust gas system (Opel Frontera B)

The exhaust system consists of an exhaust pipe with a catalytic converter and mufflers. Cars with a V6 engine have two exhaust pipes. The exhaust system ensures the removal of exhaust gases into the atmosphere, reducing the concentration of pollutants, reducing engine noise to the required level with minimal loss of engine power. In order for the exhaust system to perform its functions, it must be in good working order. The condition of the exhaust system also affects engine power and fuel consumption.

Mufflers are designed to smooth out pulsations in the exhaust gas flow and reduce noise levels.

The oxygen concentration sensor is mounted in front of the catalytic converter, which ensures the combustion of harmful substances contained in the exhaust gases. Depending on the oxygen content in the exhaust gases, the oxygen concentration sensor induces a voltage of 0 to 1 V. Based on this data, the engine control unit changes the opening time of the injectors and the ratio of fuel in the air-fuel mixture. In order for the combustible mixture to burn completely and for the exhaust gases to be free of harmful substances, there must be 1 part fuel per 14.7 parts by weight of air.

When repairing, the exhaust system parts can be replaced individually. Self-locking nuts and seals must be replaced with new ones after each dismantling.

The pipe hanger retaining rings and rubber cushions should be checked for damage and cracks and, if necessary, also replaced with new ones.

When installing new exhaust pipes, it is recommended to replace all fasteners with new ones. The catalytic converter is designed to reduce the level of harmful substances in exhaust gases. It consists of a ceramic porous frame covered with a protective layer containing salts of noble metals that ensure the process of cleaning exhaust gases.



The purpose of the exhaust gas recirculation valve is to divert part of the exhaust gases back into the combustion chamber in order to reduce the ignition temperature of the fuel-air mixture and thereby reduce the content of harmful substances in the exhaust gases.

To avoid damage to the catalytic converter, follow these guidelines:

• Use unleaded petrol only.
• Perform forced starting of the engine by pushing or towing only once and for a distance of no more than 50 meters, but it is best to use an auxiliary battery in this case. Unburned fuel, when ignited, can cause overheating and destruction of the catalytic converter. If the engine is warm, then forced starting by pushing or towing is not allowed at all;
• If the engine has difficulty starting, do not operate the starter for too long. When the engine is started, fuel is continuously injected. In such cases, it is necessary to find and eliminate the cause of the malfunction;
• Monitor the amount of fuel in the tank and do not allow it to run out completely;
• If misfires are observed, it is necessary to avoid high engine speeds and immediately eliminate the malfunction;
• Install only the spark plug types recommended by the vehicle manufacturer;
• Do not perform spark testing with the spark plug cap removed;
• Do not compare cylinders by cutting off ignition in the combustion chamber of one cylinder. With such a shutdown, including with the help of a stand for checking the engine operation, unburned fuel gets into the catalytic converter;
• Do not park your vehicle over dry leaves or grass. The exhaust system in the area of the catalytic converter is very hot and emits heat even after the engine is turned off;
• When filling and topping up engine oil, pay special attention to not exceeding the maximum oil level mark on the dipstick: Excess oil, due to incomplete combustion, gets into the catalytic converter and can damage the precious metal or completely destroy the catalytic converter.

Exhaust leaks in the exhaust system are usually caused by damaged gaskets and leaking pipe connections or damage to the mufflers caused by impacts while driving. Exhaust gas leaks lead to increased noise and vibration from the contact of exhaust system components with the vehicle body.



Before removing or disassembling exhaust system components, soak the bolts and nuts securing the exhaust system components with a fluid that loosens the connections. Wait 5 minutes for the liquid to penetrate the threaded connection.

After working on the exhaust system, move the vehicle's exhaust system to the sides to make sure it does not touch the vehicle body. Otherwise, replace the rubber exhaust mounts.

(Article posted on an online resource OpelBook.ru)

Warning: Make sure the exhaust system is sufficiently cool before removing or inspecting components.