Note. To avoid violating the warranty obligations that apply to components of exhaust gas reduction systems, check and maintain the catalytic converter in the workshop of a car service station.
General information
A catalytic converter is a component of exhaust gas toxicity reduction systems, is included in the exhaust system and serves to reduce the emission of toxic components into the atmosphere. The vehicles discussed in this Manual use two types of catalytic converters. A conventional oxidation converter reduces the content of hydrocarbons and carbon monoxide in the exhaust gases. A three-function catalytic converter additionally reduces the emission of nitrogen oxides (NOx).
Examination
Diagnostic equipment to check the catalytic converter is expensive and extremely difficult to operate. If you suspect a converter failure, take the car to a service station for inspection.
1. Every time the vehicle is raised above the ground for any reason, inspect the converter for signs of mechanical damage, traces of leaks and corrosion development. Check the condition of the welds and the reliability of tightening the flange bolts that secure the device to the sections of the exhaust system. A defective catalytic converter must be replaced.
2. Despite the reliability of the converter design, there is a fairly high probability of its blockage. The simplest way to check the patency of the converter is to check using a vacuum gauge:
- a) Connect a vacuum gauge to the intake manifold;
- b) Open the throttle valve and increase the engine speed to 2000 rpm;
- c) Release the gas quickly;
- d) If the transducer patency is not impaired, the vacuum should quickly drop by no more than 51 mm Hg relative to the norm;
- e) If the meter does not register a vacuum of 127 mmHg or higher, or fluctuates rapidly around the higher value before returning to the original value, then the exhaust system or catalytic converter is not functioning properly.
Replacement
See Chapter Power and exhaust systems.