Catalytic converter — inspection and replacement (Mazda Capella GF)

Contents: General information ⇓ Examination ⇓ Replacement ⇓

Note: The catalytic converter may have an extended warranty that is separate from the vehicle warranty. Before replacing the catalytic converter at your own expense, consult your dealer.

General information

1. The catalytic converter is part of the exhaust system and is designed to reduce the content of harmful components in the exhaust gases. There are two types of neutralizers. A conventional two-component neutralizer reduces carbon monoxide CO (carbon monoxide) and HC hydrocarbons by oxidation in the presence of a catalyst. In addition to CO and HC, the three-component neutralizer also reduces the content of nitrogen oxides NOx. The models described in this manual are equipped with a three-component neutralizer.

Examination

2. The equipment for testing the neutralizer is very expensive and difficult to operate. If you suspect that the neutralizer is not working satisfactorily, contact a specialized service station to have it checked or replaced.

3. If the vehicle is raised for any work underneath, inspect the catalytic converter for leaks, corrosion, dents, or other damage. Check the flanges that secure the neutralizer to the exhaust pipes. If there is significant damage, the neutralizer must be removed.

4. The gases inside the neutralizer flow through many thin capillaries, which are easily clogged. You can check the exhaust system for blockages as follows:

[Original version of the article on the website: MAZBOOK.ru]

a) Connect a vacuum gauge to the vacuum test port on the intake manifold.
b) Warm up the engine to operating temperature, turn on "neutral" in the gearbox (manual transmission) or "parking" (automatic transmission) and apply the parking brake.
c) Read the vacuum gauge reading with the engine idling.
d) Quickly open the throttle valve and close it again. Note the vacuum gauge reading.
d) Repeat this test three more times, recording the vacuum gauge reading each time.
e) If the vacuum after the fourth test has become less than at idle speed by at least 25 mm, then the exhaust system may be clogged (most likely a neutralizer, but it could be any other element of the exhaust system).

Replacement

5. Wet the fasteners of the catalytic converter flanges to the exhaust pipes with a liquid that penetrates the threaded connections (figure 20.5, a, b).