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

Every year, the world is tightening environmental standards. At the moment, in the countries of the European Union, cars with an exhaust of at least "Euro-4" are used. In Russia, less demanding for the environmental compatibility of exhaust gases. However, even the modern "Lada" and "GAZ" are equipped with such a device as a catalyst. What is this element? How does he work? How to check the serviceability of the catalyst? About all this and not only - later 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 intake pipe (if there is a resonator in the car, 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 down harmful substances, preventing them from entering the atmosphere. The exhaust becomes cleaner and less harmful to the environment.

Design

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

• Shells.
• The carrier block.
• Thermal insulation.

How does it all work? The main element of any catalyst is a carrier unit. It is made of ceramics. This is the most expensive component in the neutralizer. Inside the element (in the core) there are a lot of cell-cells, which you can see in the photo below. So the catalyst looks in a cut. Exhaust gases pass through these honeycombs. Thanks to them, the area of contact of gases with catalyst substances is significantly increased. The next layer is thermal insulation, which reduces the loss of heat inside the device. After all, harmful substances must be afterburned, 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's thick enough, so it's impossible to burn it like a silencer. Moreover, there is a layer of thermal insulation.

How it works?

How do gases, passing through the catalyst, be cleaned of harmful substances? Everything is very simple. Inside the ceramic block there are catalyst substances. This is palladium and platinum, as well as rhodium. These substances contribute to the acceleration of chemical reactions. Thus, unburned carbon oxides are converted into carbon dioxide, and hydrocarbons into water vapor.

The efficiency of the catalyst is achieved only under conditions of high temperatures, not lower than 400 degrees Celsius. That is why the device is located just behind the intake manifold 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 accelerate chemical processes, you must always maintain a high temperature in the catalyst. How can this be achieved? For this purpose, an oxygen sensor is installed in the device . It reads the required information about the exhaust, and then transmits the signal to the control unit. And already from the ECU comes the signal to the intake manifold, where the composition of the fuel-air mixture changes. Due to such adjustments, the electronics automatically maintains 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? The first way

Any neutralizer is designed for a certain period of operation. Usually these devices serve 200 thousand kilometers. At the end of this period, a sufficient number of unnecessary substances accumulate inside the core, which clog it. How to check the catalyst on the machine without removing it? This can be determined by indirect evidence:

• The car begins to overspend the fuel.
• The thrust disappears.
• There is a sharp smell of hydrogen sulfide.
• Difficult start of the engine. And this happens even "on the hot". The reason for this is a clogged catalyst. Exhaust gases are difficult to overcome the contaminated mesh.

All these symptoms can be accompanied by a yellow warning lamp on the instrument panel. It looks like the picture below. If the CHECK lights up on the instrument panel , and the behavior of the car has changed for the worse, this is an excuse to think about the catalyst clogging.

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 carbon black. Also, cases where the catalyst cells are simply melted are not uncommon. In the section this phenomenon looks as follows. This means that the element is clogged, and it should be replaced. The same symptoms can also occur in diesel engines, where a particulate filter is used instead of the catalyst . Do not ignore these symptoms.

How to check the catalyst for clogging? Method number 2 - a manometer

The essence of this method is to check the exhaust system for back pressure. How to check the catalyst for clogging? For this we need a manometer and an adapter. The latter should be of such a diameter that it snaps into the place of the oxygen sensor. So, we twist the lambda probe and install a pressure gauge with an adapter there. How to check the catalyst? We start the engine, raise the revolutions to 2.5 thousand and look at the readings. The normal pressure should be at least 0.34 kgf per square centimeter. If the level is less, then the element is clogged.

In this way, you can check the catalyst VAZ 2170 or any foreign car. The only problem is the difficulty in dismantling the oxygen sensor. Often, it "sticks" to the catalyst. It is also necessary to achieve maximum tightness of the joint. If the exhaust "cuts", the testimony will be inaccurate.

The third method is a motor tester

How can I check if the catalyst is clogged? You can use the motor tester. For this purpose, instead of a spark plug, a control sensor is installed, which fixes the pressure in the system. Further on the computer the oscillogram is removed, on the basis of which the conclusion about the serviceability of the catalyst is taken. The method is quite accurate, but not everyone has a motor tester at their fingertips. Often this service can be ordered at specialized service stations.

The fourth way is visual inspection

How to check the catalyst yourself? This method is available to everyone, but we immediately note its disadvantages. You will certainly have difficulty in dismantling the item. Often the bolts are tightly "boiled", and they can only be cut off by a Bulgarian. Of course, you can replace them. But this is additional spending. By removing the element, you will see the state of the cell cells. If there are traces of reflow on their surface, such a catalyst is no longer usable. Frequently, instead of it, a conventional spacer or flame arrestor is installed. Since the element contains expensive metals inside, its price is from $ 500. The cheapest way is to install a flame arrester with the computer firmware. In the block, the cleaning element is cut out, so that the CHECK inscription does not appear on the panel in the future.

Conclusion

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