How to check the catalyst for clogging: step by step instructions, device and recommendations

2024 Author: Erin Ralphs | [email protected]. Last modified: 2024-02-19 11:42

Ecological standards are getting tougher in the world every year. At the moment, in the countries of the European Union, cars with exhaust emissions not lower than Euro-4 are used. In Russia, they are less demanding on the environmental friendliness of exhaust gases. However, even the modern Lada and GAZ are equipped with a device such as a catalyst. What is this element? How does he work? How to check the he alth of the catalyst? All this and more - further in our article.

Characteristic

So what is a catalyst? This element is one of the components of the exhaust system. The catalyst is located in front of the muffler, after the exhaust pipe (if the car has a resonator, then in front of it).

The full name of the device is a catalytic converter. What does it serve? This device is designed to reduce the toxicity of exhaust gases. Thus, the catalyst burns out harmful substances, preventing them from escaping into the atmosphere. Exhaust becomes cleaner and less harmful to the environment.

Design

Let's look at the catalyst device. This element consists of several parts:

• Cases.
• Carrier block.
• Heat insulation.

How does it all work? The main element of any catalyst is a carrier block. It is made from ceramic. This is the most expensive component in the converter. Inside the element (in the core) there are many honeycombs, which you can see in the photo below.

This is how the catalyst looks in section. Exhaust gases pass through these cells. Thanks to them, the area of contact of gases with catalyst substances is significantly increased. The next layer is thermal insulation, which reduces heat loss inside the device. After all, harmful substances must be burned, and for this it is important to reach the maximum temperature in the ceramic core. And finally, all this is placed in a metal case. It is thick enough, so its burnout, as on a muffler, is excluded. Moreover, there is a layer of thermal insulation.

How does it work?

How are gases passing through the catalyst purified from harmful substances? Everything is very simple. Inside the ceramic block there are substances-catalysts. These are palladium and platinum, as well as rhodium. These substances help speed up chemical reactions. Thus, unburned carbon oxides are converted into carbon dioxide, and hydrocarbons into water vapor.

The efficiency of the catalyst is achieved only at high temperatures, not lower than 400 degrees CelsiusCelsius. That is why the device is located immediately behind the exhaust pipe of the exhaust manifold. However, it is not always possible to reach such a temperature, especially in winter at the start. Therefore, part of the exhaust is not cleaned, and passes through the cleaner "idle".

To increase efficiency and speed up chemical processes, you must always maintain a high temperature in the catalyst. How to achieve this? To do this, an oxygen sensor is installed in the device. It reads the necessary information about the exhaust, and then sends a signal to the control unit. And already from the ECU a signal is sent to the intake manifold, where the composition of the fuel-air mixture changes. Thanks to such adjustments, the electronics automatically maintain the desired temperature inside the catalyst. Due to the enrichment of the air mixture, the heating of the elements increases.

How to check the catalyst without removing it? First way

Any neutralizer is designed for a certain period of operation. Typically, these devices serve 200 thousand kilometers. After this period, a sufficient amount of unnecessary substances accumulate inside the core, which clog it. How to check the catalytic converter on a car without removing it? This can be determined by indirect signs:

• The car is starting to run out of fuel.
• Loss of thrust.
• There is a strong smell of hydrogen sulfide.
• Difficulty starting the motor. And this happens even "hot". The reason for this is a clogged catalytic converter. It is difficult for exhaust fumes to pass through a contaminated mesh.

All these symptoms may be accompanied by yellowindicator lamp on the instrument panel. It looks like the photo below.

If the CHECK light is on on the instrument panel, and the behavior of the car has changed for the worse, this is a reason to think about the clogging of the catalyst.

Why is this happening?

There are only a few reasons for this phenomenon. This is the destruction of the catalytic layer or the ceramic component, or the contamination of the cells with soot. It is also not uncommon for catalyst cells to simply melt. In the context of this phenomenon is as follows.

This means the element is clogged and should be replaced. The same symptoms can occur in diesel engines, where a particulate filter is used instead of a catalyst. These symptoms should not be ignored.

How to check the catalyst for clogging? Method number 2 - pressure gauge

The essence of this method is to check the exhaust system for backpressure. How to check the catalytic converter for clogging? To do this, we need a pressure gauge and an adapter. The latter should be of such a diameter that it tightly fits into the place of the oxygen sensor.

So, we unscrew the lambda probe and install a pressure gauge with an adapter there. How to check the catalyst? We start the engine, raise the speed to 2.5 thousand and look at the readings. Normal pressure should be at least 0.34 kgf per square centimeter. If the level is less, then the element is clogged.

This way you can checkcatalyst VAZ 2170 or any foreign car. The only problem is the difficulty in dismantling the oxygen sensor. Often he "sticks" to the catalyst. It is also necessary to achieve maximum tightness of the connection. If the exhaust "cuts", the readings will be inaccurate.

Third way - motor tester

How to check if the catalytic converter is clogged? You can use a motor tester. To do this, instead of a spark plug, a control sensor is installed that records the pressure in the system. Next, an oscillogram is taken on the computer, on the basis of which a conclusion is made about the serviceability of the catalyst. The method is quite accurate, but not everyone has a motor tester at hand. Often such a service can be ordered at specialized service stations.

Fourth method - visual inspection

How to check the catalyst with your own hands? This method is available to everyone, but we immediately note its disadvantages. You will certainly have difficulty dismantling the element. Often the bolts "stick" tightly, and they can only be cut off with a grinder. Of course, you can replace them.

But that's an additional expense. After removing the element, you will see the state of the honeycombs. If there are traces of melting on their surface, such a catalyst is no longer suitable for use. Often, instead of it, a conventional spacer or flame arrester is installed. Since the element contains expensive metals inside, its price is from $500. The cheapest way out is to install a flame arrester with ECU firmware. A cleaning element is “cut out” in the block so that the inscription does not appear on the panel in the futureCHECK.

Conclusion

So, we found out how to check the catalyst with our own hands, how this element works and works. Look at the odometer reading and listen to the operation of the motor. If the car is quite old, be sure to remove the catalyst - the car will be much easier to "breathe".