Catalytic converter (Opel Corsa B)

All Corsa and Tigra vehicles with petrol and diesel engines are equipped as standard with catalytic converters for cleaning engine exhaust gases.

The catalytic converter has a central ceramic part of a honeycomb structure, covered with a layer of salts of noble metals, which act as a converter. The catalytic converter is fixed in the housing by means of an insulating support layer, which simultaneously compensates for the thermal expansion of the catalytic converter.

The EFI system in combination with the lambda probe precisely regulates the amount of fuel injected so that the catalytic converter can reduce the amount of harmful substances in the exhaust gases. The lambda probe is located in the downpipe before the catalytic converter and is washed by the exhaust gas flow. The lambda probe is an electrical measuring element that determines the oxygen concentration in the exhaust gases by changing the voltage and thus allows the quality of the air-fuel mixture to be adjusted. Within a fraction of a second, the lambda probe can transmit corresponding signals to the ECM, which allows continuous adjustment of the quality of the air-fuel mixture depending on changing operating conditions (idle, full throttle). This ensures optimum combustion of fuel in the catalytic converter.

In order for the fuel to be burned in the catalytic converter at a temperature of 300÷800 degrees, the air-fuel mixture must be slightly depleted of air.



Petrol engines use a three-way catalytic converter, which reduces the content of carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NO x) in the exhaust gases.

Diesel engines use an oxidation catalytic converter because oxygen regulation is not required. This catalytic converter reduces the concentration of carbon monoxide and hydrocarbons contained in the exhaust gases. In addition, it reduces the exhaust odor characteristic of diesel engines.

Catalytic converter and EGR system

Concentrations of nitrogen oxides (NO x) in exhaust gases 1.0 and 1.2 l engines, as well as DOHC 1.4 and 1.6 l engines produced since 09.1994 is maintained at a low level before the catalytic converter thanks to the EGR system.

EGR valve on dOHC engines 1.0 and 1.2 l located on the end face of the cylinder head; on other engines, it is located on the exhaust manifold and is controlled by the ECM. The EGR's job is to divert some of the exhaust gases into the engine's combustion chambers in order to reduce combustion temperatures and thus reduce the concentration of harmful substances.

Cleaning exhaust gases by supplying additional air

The task of supplying additional air to dOHC engines 1.4 and 1.6 l since 09.1994 is to reduce the concentration of harmful substances in the engine exhaust gases during engine warm-up. The electric pump supplies fresh air to the engine exhaust ducts to ensure afterburning of unburned compounds in the exhaust gases. Due to this, the concentration of harmful hydrocarbons and carbon monoxide is reduced. In addition, the exhaust gas temperature increases, due to which the catalytic converter warms up faster and oxygen regulation begins to operate. The ECM switches off the supply of additional air with the activation of oxygen regulation approximately 1÷2 minutes after a cold start.

Safety precautions when operating vehicles equipped with a catalytic converter

To avoid damage to the lambda probe and catalytic converter, be sure to follow these recommendations:

Petrol engines

Use only unleaded gasoline. If leaded gasoline is added by mistake, the catalytic converter and the intake pipe in front of it must be replaced. At least two tank fills with unleaded gasoline must be used before installing new components.

It is better to avoid starting a warm gasoline engine by pushing or towing. Use an auxiliary battery for this purpose. Unburned fuel, when ignited, can lead to overheating and destruction of the catalytic converter.

Avoid frequent consecutive cold starts. Otherwise, unburned fuel accumulates in the catalytic converter, which burns when heated and, detonating, damages the catalytic converter.

If you have difficulty starting the engine, do not turn on the starter for a long time, as this will continuously inject fuel. Find and eliminate the cause of the malfunction.

If there are ignition faults, to identify the source of the fault, exclude fuel injection when the starter is engaged. To do this, disconnect the fuel pump relay located in the front passenger footwell, in front of the A-pillar, behind the side trim.

Do not test spark plugs for spark with the spark plug connector disconnected.

Material copied from the portal: Opelbook.ru

Do not disconnect the ignition from any cylinder, as this will allow unburned fuel to enter the catalytic converter.

If misfiring occurs, do not increase engine speed and correct the problem immediately.

Petrol and diesel engines

Do not park the vehicle over dry grass or leaves, as the exhaust system may become hot in the area of the catalytic converter and could cause a fire.

Make sure that the engine oil level does not exceed the MAX mark on the dipstick. Due to incomplete combustion, oil may enter the catalytic converter and cause its malfunction.