What is an exhaust pipe

§ 47c StVZO (The exhaust and the discharge of exhaust gases)

Regulations for the discharge of exhaust gases

The functionality of the exhaust system and the entire exhaust system of vehicles is not only important for the environment. The self-endangerment for the drivers of the vehicles should also be prevented. If there are defects or deficiencies in the exhaust, the exhaust gases can also penetrate into the interior of the vehicle. But what are the dangers of this? And which provisions does Paragraph 47c of the Road Traffic Licensing Regulations (StVZO) meet?

FAQ: § 47c StVZO (exhaust)

What is § 47c StVZO about?

Section 47c StVZO specifies the manner in which exhaust pipes must be attached to motor vehicles.

What am I going to do if my exhaust extends beyond the side or rear of my vehicle?

In this case you have to reckon with a € 20 fine.

Can I modify my exhaust pipe in any way?

No, you have to comply with the applicable regulations. For example, you should make sure that, if necessary, the new components of the exhaust (exhaust manifold, catalytic converter or tailpipe) have an ABE or a partial certificate. You'll find more about it here.

Table of fines for § 47c StVZO

TBNROffensePenalty (€)
347012The exhaust pipe of the vehicle you are driving protruded beyond the side / rear boundary.20

The exhaust system in vehicles

For the derivation of the Exhaust gases that result from the combustion of fuels in vehicle engines, significantly more components are required than just the actual exhaust - the tailpipe. The individual components include:

1. Exhaust manifold:

The exhaust or exhaust manifold is that actual connection piece between the combustion chamber of the engine and the tailpipe of motor vehicles. Positioned directly on the engine, the slightly curved pipe directs the combustion gases produced into the exhaust system. If there are defects in the connection between the engine and the exhaust manifold, serious consequences can arise: The combustion gases can no longer be diverted properly and can even penetrate the interior of the car.

The included Carbon monoxide can quickly affect the occupants of the vehicle. The odorless gas prevents oxygen from being absorbed into the blood. People feel increasingly tired because the cells can no longer be supplied with enough oxygen. To prevent this deadly danger, you should have the vehicle checked regularly during the general inspection.

2. catalyst:

In the vehicle's catalytic converter, chemical processes - Oxidation and reduction - Filtered out components of the exhaust gases that are harmful to the environment. These include, in particular, carbon monoxide and nitrogen oxide. In order to keep pollutant emissions as low as possible, the catalytic converter is mandatory on every vehicle with a combustion engine. An additional nitrogen oxide catalytic converter is required for diesel engines, since the reduction is not possible to the same extent as for gasoline engines.

The chemical processes in the catalyst:
The exhaust gases from internal combustion engines mainly contain toxic substances Carbon monoxide (CO), hydrocarbon (CnHm) and nitrogen oxide (NO). The reaction with oxygen produces CO and CnHm to carbon dioxide (CO2) and water (H2O). Nitric oxide is produced by reacting with carbon monoxide reduced to nitrogen (N2) - associated with the creation of CO2.

The expansion or the Manipulation of cat for the purpose of supposedly increasing the performance of the vehicle are not permitted and inevitably lead to the loss of the operating license. In this case, you must also expect investigations from the tax office.

By removing the catalytic converter, the emission class on which the vehicle tax is based no longer corresponds to the actual exhaust gas emissions, so the vehicle taxes paid were too low. The fact of the tax evasion to Section 370 Tax Code (AO) is to be assumed in this case. A violation can face high fines and even imprisonment of up to five years.

3. Silencer:

A distinction can be made between Front, middle and rear silencers. These are usually distributed over the entire exhaust system. Mufflers are used to Reduce noise emissions from vehicles and exhaust systems. A distinction must be made here between so-called absorption and reflection silencers.

A Absorption silencer is usually filled with porous materials such as glass wool. These absorb the sound waves that are created by the combustion of the fuel and thus reduce the volume of the muzzle noise of the exhaust system. Specific Sports silencer are mostly lined with steel wool. This is more resilient and permanent and allows the deeper tones to penetrate in particular. The car exhaust sounds much sportier. Sports silencers can be found in tuning, especially in exhaust systems for motorcycles.

Reflection silencer however, consist of several chambers through which the sound is conducted. The sound waves are thrown back from the walls of the individual chambers - reflected - and cancel each other out a little. This also reduces noise emissions.

4. Tail pipe:

Via the tailpipe - the exhaust in the colloquial sense - the filtered exhaust gases are finally released into the environment.

The exhaust systems are on all vehicles optimized for the respective engines as standard. Replacing individual components usually only has a slight effect on performance. This can only really take effect when the entire exhaust system on motorcycles, cars and co. And other software changes (chip tuning) are changed.

Modification of the exhaust system

Particularly when tuning, individual components or the complete exhaust system exchanged. But caution is always advised. Not everything that pleases is allowed. In addition to numerous regulations on environmental and noise protection, the vehicle dimensions must always be complied with.

When attached new exhaust pipes or an exhaust cover the dimensions can be exceeded quickly. Therefore, there are a few points to consider. But what are these modifications used for?

The Mounting a panel on the exhaust system is relatively straightforward. Above all, it serves to adapt the exhaust pipes aesthetically. On the car, the tailpipe of the exhaust can be clearly identified. All other components of the exhaust system remain invisible to road users.

In order to gain a particularly sporty appearance, covers can be placed over the tailpipe for fairly light work. These give the impression that the car has a sports exhaust system.

When attaching an exhaust cover, however, in accordance with 47c StVZO, it is important to note that this must not protrude beyond the actual tailpipes. Otherwise the dimensions of the motor vehicles would not be adhered to and a warning fee of 20 Euros threatens. In the event of an inspection, the officers can also request that you remove the cover before you can continue your journey.

In addition, the cover on the exhaust must be firmly fixed to the tailpipe of the vehicle be to prevent falling off. As a rule, no approval by a testing organization is required to attach a cover to the exhaust. If you have a general operating permit for vehicle parts, you usually have nothing to fear. If necessary, however, always ask a reputable workshop beforehand which points you need to consider when installing.

Ultimately, however, these devices are only one type of Masking. No changes are necessary to the exhaust pipe itself. The effect is primarily of an optical nature. If you want to change the sound of your vehicle via your exhaust, however, far more extensive modifications are required.

To make the exhaust louder, you can do the modifications to the silencers as well new tailpipes be attached. Unlike the covers, these are not to be pushed onto the exhaust tailpipes, but instead replace them completely. To do this, the old pipes of the exhaust system must be removed.

Fitting new exhaust parts requires some skill. The new exhaust must firmly connected to the muffler become. Often only welding is possible. In addition, however, further equipment is required in order to be able to seal the exhaust properly. These include, above all, the exhaust flange and the exhaust pipe connector.

Also at Replacement of entire exhaust systems the dimensions can be decisive. Not every exhaust system fits every car. For this purpose, the corresponding specifications must be observed, which can be found in the ABE or the parts certificate. If you install an exhaust that is not approved for your vehicle, not only can the operating permit expire. The vehicle dimensions may also no longer be adhered to.

Do you want to make your exhaust louder? In any case, make sure that the permissible noise limit values ​​are not exceeded. You can see from your vehicle registration certificate (registration certificate, part I) which limit values ​​apply to your vehicle. As a rule, however, an exhaust pipe must not be louder than 80 decibels, even with older models.

Exhaust with valve control

When installing an exhaust with so-called Flap control you must in any case note that since Mid 2016 the installation or equipping of vehicles with these tuning devices is no longer permitted.

Vehicles that were previously equipped with such exhaust systems may continue to retain their registration, provided that the conversion measures can be legitimized by submitting a test certificate according to the regulations.

To the vehicle dimensions

Which dimensions are permitted according to the Road Traffic Licensing Regulations? And when are violations? The extensive regulations on prescribed vehicle dimensions can be found in Section 32 of the Road Traffic Licensing Regulations (StVZO).

The following values ​​generally apply to cars:

  • maximum width: 2.50 meters
  • maximum length without trailer: 4.00 meters

The exact dimensions of your car can be found in Part I of the registration certificate. If the exhaust protrudes too far over the side of the vehicle or over the rear, this is a violation. Unlike the exhaust system, however, The following components are not taken into account in the latitude and longitude measurement:

Repair the exhaust

Should you or the TÜV have a malfunction on the exhaust pipe of the motor vehicle, there are numerous ways to repair the system. The replacement of the entire exhaust system is not always called for. In the case of minor damage, the following measures are sufficient:

  • Exhaust pipe connector: A clamp is attached to the exhaust, which better closes and stabilizes the pipe connections. Any leaks can be repaired without incurring horrific costs. An exhaust flange also serves to better seal the pipe connection.
  • Temporary repair on the exhaust with heat protection tape: If the exhaust is loose, it can also be attached with the help of a heat-resistant strap. However, this repair can only be temporary. This is not a permanent solution. In addition, the would be recognized and acknowledged as a serious defect at the latest during the next main inspection. Is the Muffler loose, you must not simply attach it to the car with a piece of rope or the like. Exhaust systems also become extremely warm due to the emission of hot combustion gases. Only heat-resistant materials can survive this.
But also in this case: The repairs to the exhaust and tailpipe must always be carried out by specialists and Approved by the TÜV be. Otherwise the vehicle registration can expire - and with it often the insurance cover.
(30 Ratings, average: 4,70 of 5)
§ 47c StVZO (The exhaust and the discharge of exhaust gases)
4.7530Loading ...