Exhaust Systems

Automotive exhaust systems are an essential safety part of your vehicle and play a vital role in the performance, fuel economy and operating systems governed by many emission control regulations.

The components of an exhaust system vary considerably depending on the manufacturer's and country's requirements.

Its primary purpose is to reduce both the emission and noise pollution created by the everyday workings of your vehicle's engine.

While some components are common to both petrol and diesel systems, others are not, and diesel-powered vehicles often require a different approach to periodic maintenance and procedures to keep the system operating.

So what is the primary function of an exhaust system?

As your vehicle operates, the internal combustion engine creates explosions that push the pistons in the engine, creating the power we feel when the engine is operational.

This combustion process produces leftover gases and contaminants that need to be disposed of, this is the role of your vehicle's exhaust system components.

An exhaust system and its components must be in good working order to efficiently perform its role, whether redirecting gases to be fired again in the engine (EGR valve) or directing exhaust gases to the tailpipe.

The gases produced are dangerous to the human body, typically carbon dioxide, carbon monoxide, nitrogen oxides, and hydrocarbons. While we can't see these gases, we don't want them entering the engine compartment or cabin, so one of the main jobs of the exhaust system is to redirect these gases out the tailpipe at the rear of the vehicle.

With other components of the exhaust system, in place to reduce noise and harmful emissions entering the air around us.

With two basic types of fuel systems in use, Petrol and Diesel, exhaust systems are designed to suit each fuel system and process the leftover gases and carbons each produces.

Components of a typical vehicle's exhaust system

Exhaust Manifold Header

When the exhaust gases leave the cylinder head where the explosions occur, they enter the manifold designed to gather all these gases and direct them away from the engine bay and cabin area.

Sometimes original cast iron manifolds are replaced with extractors to increase exhaust flow and improve engine performance, the principle remains the same.

The Catalytic converter

Its role is to convert the poisonous exhaust gases from the engine into gases that are less harmful to the atmosphere. The nature of what they do and how they operate means they require maintenance and replacement occasionally.

This should always be diagnosed and attended to by a qualified technician, removing a catalytic converter from a system and not replacing it is illegal.

The removal of poisons is its role, and it is very efficient when working correctly.

The Exhaust Pipe

There are several different configurations of exhaust pipe systems, two common examples are

The single system (1 tailpipe at the rear of the vehicle) or

The twin system, (2 tailpipes at the rear of the car)

The piping connects the various components and directs the gases away from the vehicle.

Due to the heat generated in an exhaust system, sometimes the piping builds up condensation that sits in the pipes and may eventually rust. This causes the system to become noisy and allows gases to escape under the vehicle instead of being directed out the rear.

A damaged system will usually generate an increase in noise and should be inspected and serviced by qualified technicians.

Resonators and Mufflers

Both of these components are about reducing noise pollution to an acceptable level.

A resonator is a part of the system that encases part of the exhaust pipe, designed to reduce specific noise frequencies.

A muffler receives exhaust gas and internally redirects it through a series of chambers designed to reduce the noise emitted at the tailpipe.

These are the essential components of an exhaust system.

With the requirement to decrease harmful emissions entering the atmosphere and the requirement for increases in fuel economy, various other exhaust components play a vital role in the correct operation of your engine and its exhaust.

Modern exhaust systems are monitored, delivering information to your car's computer and reacting to different climatic conditions and driving situations, so a correctly operating system is vital.

A fault in the system will alter the data sent to the computer and affect your vehicle's efficiency and performance.

A word about Diesel systems.

A diesel vehicle often produces a carbon build-up in the system that must be dealt with, so modern diesel systems usually require more maintenance than their petrol counterpart regarding exhaust systems and their performance.

The worst condition for an exhaust system is a partial or even complete blockage of the system.

You then have an engine delivering extreme force to the exhaust manifold that cannot escape into the atmosphere at an acceptable flow rate.

It's like blowing up a balloon, eventually, something has to give way.

Unfortunately, it is usually your vehicle's engine, causing an expensive catastrophic failure that could have been avoided.

If you have a diesel vehicle, ask your local Future Auto Service Centre what your system requires. They have a wealth of experience and knowledge and are happy to assist.

Some other components you may hear of are

• DPF's or Diesel Particulate filters
• EGR's or Exhaust gas recirculation valves.
• Add Blue, a fluid required by some diesel systems to reduce emissions.
• Oxygen sensors sample the levels in the exhaust system and deliver the information to the engine management system.

As emission regulations get tighter, more components are being developed and added into exhaust systems.

 Important information

• Exhaust systems run at extremely hot temperatures, never work on a hot exhaust.
• Exhaust systems produce dangerous gases, never work on an exhaust system in a confined space.
• Exhaust systems are set to work within legally set emission levels, it is illegal to tamper with these levels and adjustments.
• If a component in an exhaust system fails, it is often the result of another issue that must be addressed.
• Ignoring the Exhaust system problems leading to complete engine failure, requiring a replacement engine and the original exhaust repair.

When we service your vehicle at Future Auto Service Centres, we carry out an external inspection of your exhaust system and report any issues that require attention.

However, if your system suddenly becomes noisy or you experience a lack of engine power, contact your local Future Auto Service Centre for an urgent inspection.

Our service centres are equipped with the tools, diagnostic equipment and fully trained staff to ensure your satisfaction and safety regarding your vehicle's exhaust systems.