Is water dripping from the catalytic converter? This is why

Not everybody is quite familiar with catalytic converters and how they work. If you have no idea of what it is, then it means you miss a lot.

But for those who already know, catalytic converters fully understand how they work and can tell when they have any abnormalities.

One of the abnormalities you might see with your car’s catalytic converter is water leaking out of it. While you might be worried when you see it, this can be a normal thing with your car that you shouldn’t worry about.

Catalytic helps convert the car’s harmful gasses to less harmful ones emitted to the environment. Therefore producing the water vapor that gets out of the catalytic converter.

Why does water leak from a catalytic converter?

Water can leak from a catalytic converter because it minimizes the amount of vapor getting out of the vehicle. The catalytic converter is responsible for oxidation and reduction of harmful gaseous emissions.

They use a reduction catalyst of rhodium and platinum that reduces nitrogen oxide. It removes the nitrogen atoms from the nitrogen oxide molecules, letting the free oxygen form oxygen gas. The nitrogen elements attached to the catalyst then react, resulting in nitrogen gas.

Moreover, the catalytic converters use oxidative catalysts made of palladium and platinum to reduce carbon monoxide and carbon dioxide. Therefore, the unburnt oxygen and hydrocarbons combine to form water and carbon dioxide.

what is a Catalytic converter

So, the end product of the oxidation and reduction process is water, and this is where the water you might see leaking out of the catalytic converter comes from.

Water out of the catalytic converter might imply that the converter is working correctly. However, if you notice a lot of water leaks out of the converter, then this is not normal; it implies there is a problem with the converter.

Reasons for water drips from a catalytic converter

1. Oxidation and reduction process byproduct

Catalytic converters convert harmful engine gas to less harmful ones safe for the environment. This makes the vehicle environmentally friendly through the oxidation and reduction process. During this process, water is produced, which is why water might leak out through the catalytic converter.

2. Condensation from engine heat

The engine heat can cause a lot of vapor to the catalytic converter. A car’s engine produces a lot of heat upon ignition, and as a result, the catalytic converter becomes hot. Therefore as temperatures outside become cooler, a vapor is created in the catalytic converter.

How do you fix a leaking catalytic converter?

Fixing a leak in the catalytic converter is easy as when noting it is leaking some contents. You can follow three essential steps to fix a leaking catalytic converter.

Step 1: Locate the catalytic converter of your car

A catalytic converter looks like a box but is made of metal and is one component making up the exhaust system. It lies between the head pipe of the exhaust from the engine and the tailpipe taking out exhaust products.

Step 2: Locate a leaky section, maybe a hole or crack

Of course, it may take you a couple of hours trying to find the exact leaky part of the catalytic converter. To locate it, allow the engine to run to allow emissions to pass through the catalytic converter and monitor where they leak through.

Step 3: Stop the engine and allow the exhaust system to cool

Running the engine will cause the exhaust system to be hot. Therefore, after stopping the engine, you need to wait for some minutes for the catalytic converter and other exhausted components to cool.

Step 4: Using a piece of steel putty, place it onto the leak hole or crack

After placing the putty, smoothen it using your finger until it flushes with the catalytic converter’s outer surface.

Step 5: Allow the putty to dry up

Once you have sealed the leak with putty, don’t start your engine immediately. You need to wait for four hours or more, and it will have dried, forming a permanent seal.

How much does it cost to fix a leaking catalytic converter?

It is not cheap fixing a leaking catalytic converter. For instance, the cost of a new catalytic converter is up to $ 2200 or more, which is almost equivalent to your car’s value. Therefore, it may cost you between $940 and $2400—this includes labor and the cost of the catalytic parts.


A leaky catalytic converter can bring worries, but water leaking out of the catalytic converter is nothing to worry about. Since a catalytic converter carries out the oxidation and reduction process to clean the car’s harmful emissions before release into the atmosphere, it produces water as the end product.

However, although it is normal to see water leaking out of the exhaust, it is essential to ascertain that it is not leaking out of a damaged catalytic converter. It is advisable to take proper measures on time to avoid damage that might be costly to repair.

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