Catalyst, DPF and Exhaust specialist.

+468996 996. Weekdays 8 AM - 5 PM.

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The Catalyst - How it works

The catalyst uses a combination of precious metals and heat to create a chemical reaction. This reaction breaks down toxic gases and makes them less harmful to the environment.

The catalyst consists of a ceramic core and a metal shell. The core structure is similar to that of a wax cake in a beehive. Its small size gives it a surface that can be measured by hundreds in cubic inches. The surface is coated with precious metals like platinum, palladium and rhodium, and the body is a shell of sheet steel. Between the shell and the core is a lining which expands when the core is heated, and keeps the core in position.

The temperature span in which a catalyst works is 350-500°C. When the catalyst reaches this temperature a chemical reaction occurs while the exhaust stream passes through the catalyst body. The harmful gases carbon monoxide, hydrocarbons and nitrogen are oxidized, and emerge as water vapor, carbon dioxide and nitrogen.

Installation Tips

It is very important to determine the cause of the old catalyst breakdown.

An exhaust test that costs about 400-500 SEK can show faulty oxygen sensors or incorrect engine settings, for example. The possible problems must be adjusted before the new catalyst is installed. Otherwise the same problem might arise again.

Exhaust paste should never be used on the front of the catalyst. Exhaust Paste will melt and clog the catalyst nucleus. All use of exhaust paste forfeits 
the guarantee.

It is recommended to replace oxygen sensors and gaskets when installing a new catalyst. Lambda sensors should be replaced folas per manufacturer recommendations, after about 150.000 to 180.000 km.

A gentle running-in of the catalyst can prolong its life. We recommend that the vehicle runs fast on idle for 10 minutes, or is driven 15 km at a calmer pace.

The Muffler

There is both a middle and a rear silencer, usually the second and third part of an exhaust system. Their mission is to muffle engine sounds to acceptable levels. Without damping, the noise is above the threshold for pain on the ears.

There are two variants of damping:

  • Throughput, where glass wool in the muffler takes up pressure waves (exhaust sound).
  • Mechanical damping, where the exhaust gas velocity is reduced by passing in a zigzag pattern through the damper. Thus it is made "more difficult" for the exhaust gases to get out and the speed of the sound waves is reduced.

The casing of the silencer is made by among other materials, aluminized steel or stainless steel. Exhaust system may be divided into sections or in one piece. Factory-installed exhaust systems are often of the latter kind. When replacing any part, a part of the old system must be shortened. Connection of replacement parts are usually done with integrated sleeves: a part of the tube on the replacement muffler.

Diesel Particulate Filters (DPF)

We have Diesel Particulate Filter for the majority of all cars.

Fixa Bildelar offers maybe the most extensive range of new particle filters for passenger cars and light trucks in Sweden. Always brand new parts with two year warranty.

You can find particulate filters for your/your customer's car via our website, chat, or by contacting our sales team at 08-996 996. On the website we have real-time inventory of our bestselling diesel particulate filters. They can be ordered with mounting kits for delivery as soon as the next day in most parts of the country. We deliver both to private clients and workshops throughout all of Scandinavia and Finland.

Save a significant amount by shopping at Fixa Bildelar. We have attractive prices since we buy directly from most of Europe's many particle filter manufacturers.

How Diesel Particulate Filters work

Diesel particulate filters are used to filter out soot and other harmful particles from diesel exhaust. In normal operation the filter converts a large portion of these particles to harmless CO2 via a process called regeneration: the temperature is raised, the soot is oxidized, and the combustion of the particles is accelerated. Regeneration works better during longer drives, but regardless of driving distance, the filter will become clogged with time and may need to be replaced.

Our diesel particulate filters are made in the following materials:

Cordierite (Cordierite) is the most common material for diesel particulate filters, and is used in most of our products. This is a heat-resistant, ceramic material with good filtration performance, with its only disadvantage that it has a relatively low melting point - 1200°C. It has happened that extremely clogged filters in this material melt during regeneration, though this is very rare. Diesel particulate filters in cordierite are common on the aftermarket, as well as in combination with catalysts.

SiC (Silicon Carbide) is a more expensive material used within our finer range. It is a compound of silicon and carbon, and has a melting point as high as 2700°C. Silicon Carbide also has 99% filtration efficiency. DPF in this material are normally used for genuine parts and catalytic diesel particulate filters.

Find Diesel Particulate Filters for your car

use our search function below to see if we have the right filters for Your car. If you can't find what you are looking for, contact us and we'll help you look!

You could search for this, for example: bmw diesel particulate lfilter




Fitting Guide


Fixa Bildelar Europa AB

Årsta skolgränd 16 C, 11743 Stockholm
Back side of house 16, customer parking by entrance.

Postadress: Fixa Bildelar Europa AB, Årsta skolgränd 16 C, 11743 Stockholm.
Orgnr: 5568678832


Since 2009, we have sold catalytic converters, silencers, diesel particulate filters and other exhaust components. We offer high quality parts to probably scandinavia's best prices. You can save up to 50% compared with spare stores in Scandinavia. Search 26,000 parts and save hundreds of Euros when you repair the car.

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