Where is the catalytic converter located?

A catalytic converter is one of the parts of an exhaust system. It can be installed inside the exhaust manifold or directly under the car and the location depends on the car age and model. Currently, the catalytic converters can be found both in petrol engine cars and compression-ignition engine-driven cars. Although different in type they are intended to play the same role.

A catalytic converter, commonly called a cat, is a part of the exhaust system responsible for removing harmful substances from the exhaust gas. Catalytic converter have been installed in petrol engine cars for many years now. Recently they have also been used in compression-ignition engine (Diesel) cars due to the stringent Euro standards for exhaust gas emission.

Catalytic converters were installed under the floor plate in older car types, while they are located in exhaust manifolds of newer car models to improve their efficiency.

Catalytic converters installed under a car

Catalytic converters located under a car is a characteristic small metal can connected to the middle and rear silencers with the exhaust pipe. It is easy to remove as the worn out converter can be screwed or cut out and replaced with a new one. Cats of that type are more often stolen.

Catalytic converters installed in an exhaust manifold

A catalytic converters installed in an exhaust manifold is more difficult to locate and replace. The manifold is a single large part which houses the catalytic converter as one of the parts. The replacement of the catalytic converter involves the removal of the entire manifold, cutting the converter open, replacing the insert with a properly selected one and, finally, welding the converter.

Sometimes a car can be equipped with a catalytic pre-converter and a main catalytic converter located downstream the exhaust system.

Why do most of new cars use the manifold? Because a housed converter can heat up more rapidly and, consequently, perform better.

Catalytic converters in Diesel engine cars

The situation is a bit different when we look at Diesel engine-driven cars. In cars of that type catalytic converters are located downstream the particulate matter filters (so-called DPFs). With such location the exhaust gas runs through the particulate matter filter first and only then it is directed to the converter. What is worth mentioning is that sometimes both those parts are installed in a single housing (resembling a metal can) instead of one.