Catalyst ("Priora"): description, specifications and reviews

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

The design of the exhaust gas system of absolutely all modern cars provides for the presence of a catalytic converter (catalyst). This is a prerequisite for complying with environmental regulations.

VAZ-2170 is no exception. Its exhaust system is also equipped with a catalytic converter. It will be discussed in this article. We will look at how the catalyst (Lada Priora) is arranged, and also talk about the problems that arise when it malfunctions. In addition, we will try to deal with alternative devices used to replace it.

Why do we need a catalyst

A catalytic converter is an element of the exhaust gas system used to reduce the amount of harmful impurities (carbon oxides, nitrogen, unburned hydrocarbon compounds) in the exhaust. This is achieved by afterburning them inside the device due to the high temperature and the presence of oxygen in the gases.

Design Features

How does a catalyst work? "Priora" in the sense of its design is no different from other modern machines. The part consists of a steel body(cans) and a working element - metal honeycombs, the surface of which is coated with an active substance that contributes to exhaust heating. The latter is a platinum-iridium alloy.

Unburned harmful impurities, passing through the cells of the device, settle on the surface of the catalytic layer and continue to burn under the action of high temperature, oxidizing almost to the end. As a result, at the output we have an exhaust with a minimum amount of harmful substances.

Location

In terms of where the catalyst is located, Priora is also unoriginal. It is located just behind the exhaust manifold, right on the exhaust pipe. You can see it if you look from the back of the engine. In other vehicles, it may be behind the downpipe.

Signs of a failed catalytic converter

The declared resource of the VAZ-2170 catalyst is 140 thousand kilometers. However, this does not mean that after this mileage the device must be changed. It can serve much longer, or it can fail even after passing 10 thousand km. It all depends on how you operate the vehicle.

How to understand that it's time to change the catalyst? "Priora", being a car stuffed with various sensors, will first of all let you know about it with a lit CHECK light on the dashboard (when reading the code, error 0420). The failure of the catalytic converter is also accompanied by:

• difficult (long) process of starting the engine;
• decrease in powercharacteristics;
• increased fuel consumption;
• floating idle;
• uncharacteristic sounds of a running motor;
• strong (acrid) smell of exhaust gases.

Start with sensor

When you notice the above signs, don't despair right away. The reason for the fact that the car has lost its former agility may be a failed oxygen sensor (lambda probe). By the way, Priora has two of them: a control one and a diagnostic one. The first is designed to determine the amount of oxygen in the exhaust gases, and the second is to inform the driver in time about a possible malfunction of the first device.

Often, these sensors are called by other people's names, for example, asking how many catalysts are in Priora and which ones. This is fundamentally wrong. Catalyst - one, sensors - two. Let's get back to them.

Given that the diagnostic lambda probe fails extremely rarely, first check the catalyst control sensor. "Priora" in the event of a breakdown will also notify you with a burning CHECK lamp. It remains only to read the error code with a scanner and decrypt it. If it turns out that there is a problem with the lambda probe, you are in luck.

How to check the catalyst

A catalytic converter can be checked in two ways: by visually inspecting it and by measuring the pressure inside the can. In the first case, the device is dismantled and its visual inspection is carried out. If the body of the device has traces of mechanical impact, and the cells visible inholes, fused, catalytic converter clearly defective.

Checking the pressure inside the can of the device is carried out using a special pressure gauge screwed in instead of the control sensor. The engine is started, warmed up and brought to 3 thousand rpm. If the catalyst is working, the pressure should not rise above 0.3 kgf/cm2.

Why does the catalyst fail

The main malfunction of the catalytic converter is the obstruction of cells. Over time, their working layer burns out, and they themselves begin to melt, turning into a continuous mass. This creates an obstacle for the free exit of exhaust gases, due to which, in fact, the engine “suffocates”.

Premature failure of the catalyst can be provoked:

• using low-quality fuel;
• oil getting into the fuel;
• violations in the ignition system.

How much does the catalyst for Priora cost

The catalyst cannot be repaired or restored. It can only be replaced. If you want to buy a new device, it will cost you about 5-6 thousand rubles, which is not very cheap. Having received a new catalyst, Priora will undoubtedly come to life, but how long will it last?

Yes, and never buy a used converter. Who knows how much he has worked and why he is being sold.

Change the catalyst on the Priore with our own hands

To replace the VAZ-2170 catalytic converter, contactservice station is not necessary. This can be done in your own garage. For this you will need:

• set of keys;
• head 13 with handle;
• pliers;
• flathead screwdriver.

Replacing the catalyst ("Priora") is carried out as follows:

1. Install the car on the viewing hole.
2. Raise the hood, disconnect the negative terminal on the battery.
3. Remove the decorative cover of the power unit.
4. Go to the viewing hole. We unscrew (not completely) the lower nut of the clamp connecting the main and additional mufflers. Loosen the top nut completely. Remove the clamp and remove the sealing ring.
5. Bend off the antennae of the catalyst heat shield with pliers.
6. Unscrew the three nuts securing the exhaust pipe flange and the catalyst flange. Remove the lock plate.
7. Raise the additional muffler up and remove its bracket from the front cushion of its suspension (rubber band).
8. Disconnect the exhaust pipe of the additional muffler from the catalyst studs. Remove the gasket.
9. Disconnect the wiring harnesses from the connectors of the control and diagnostic oxygen sensors.
10. Remove the sensor wire holders from the heat shield of the steering gear.



11. Using a 13 head, unscrew the bolts securing the catalyst to the bracket.
12. Unscrew the three fastening nutssteering heat shield. Dismantling the screen.
13. Unscrew the two nuts of the water pump pipe bracket (pump). Remove bracket.
14. Dismantle the catalyst by unscrewing the eight nuts securing it to the cylinder head. Remove the catalyst and gasket.
15. Install a new catalytic manifold in reverse order.

Before installing the catalyst, be sure to check the condition of the gasket. If it is damaged, you will have to buy a new one. Under no circumstances should a torn gasket be installed!

You should also check the flatness of the catalyst flange. This can be done by attaching to it, for example, a metal ruler. Using a feeler gauge, measure possible gaps. If they exceed 0.1 mm, we grind the flange surface.

Is there an alternative

Will Priora work without a catalyst? Of course it will be! The absence of a catalytic converter will not affect its performance in any way, as some "experienced" craftsmen claim. Yes, the car will no longer meet the established environmental standards, but it will not work worse.

If you do not want to spend money on a regular catalyst, you can always buy a universal device that will cost you half the price, including installation. In fact, it is the same catalytic converter with the same functions and similar design. Yes, and they are mainly produced at the same factories as the original ones, and the price for them is lower due to the lack of various trademarkups.

Well, if you wish to carry out an easy tuning of your Priora, buy a good flame arrester for it. It is installed instead of a catalyst. With it, the engine power will increase due to improved exhaust gas permeability, and the sound of the power unit will acquire sporty notes.

A few words about "spiders"

There is another option for tuning, which involves a complete alteration of the exhaust system. It's called "straight". Its essence is to remove from the system all the elements that prevent the free exit of exhaust gases, including the catalyst.

The main part of the forward flow is an insert ("spider"). This is an analogue of the exhaust manifold, which differs from the latter in a special pipe connection, in which the exhaust gases leaving the cylinders have practically no effect on subsequent exhausts.

Two types of spiders are installed on Priora: 4-1 and 4-2-1. The numbers indicate how the collector pipes are connected. The catalyst insert ("Priora") 4-1 provides for the connection of four pipes into one. In the "spider" 4-2-1, the collector pipes are first paired, and then converge into one.

It is believed that the optimal pipe connection for the VAZ-2170 is the 4-1 scheme, but the other is no worse. It is important that the fastening elements of all parts of the exhaust system match, because in addition to the insert, you will also need to purchase a resonator and a silencer.

How to extend the life of the catalyst

Finally, check out the tips that will help you notback to the topic of replacing the catalytic converter:

1. Do not use poor quality gasoline. This decision will save not only the catalyst. "Priora" is not at all the car in which you can pour everything that burns into the tank.
2. Don't let oil get into the fuel. Noticing that the exhaust has acquired a bluish tint, do not be too lazy to check the compression in the cylinders. Possible wear of the parts of the piston group, due to which oil enters the cylinders.
3. Pay attention to the dashboard. If the CHECK warning light comes on, and the car starts hard, loses power, do not wait with the diagnosis.