How to Fix a Clogged Catalytic Converter


If you own a vehicle, it is vital that you know the basics of car maintenance. This will not only save you lots of money but also save you from a lot of worries whenever an emergency arises.

Any vehicle maintenance process should include cleaning of the entire vehicle plus its engine.

This article will focus on the symptoms of a clogged catalytic converter and also provide you with a step by step guide on how to fix it.

How to Recognize a Clogged Catalytic Converter

Like any other car issue, a clogged catalytic converter will show in various ways. It is very important that you recognize these problems for you to be able to handle the issue in the right way.

Below are some of the most common symptoms of a clogged catalytic converter.


Overheating is one of the most common symptoms of a clogged catalytic converter. Whenever your vehicle is experiencing thermal shock, it will result in overheating. This is because a clogged catalytic converter will hinder enough gases from passing through it. This will, in turn, affect the normal functioning of the engine.

If the engine does not receive enough gases, it will have a mix of both burnt and unburnt fuel. Overheating also occurs whenever your converter comes into direct contact when it is still hot with cold water or ice.

Overheating might cause discoloration and damage to the exterior surface of the car. You can check your cold air intake and if you think your air intake do not work properly then chose a good quality air intake under your budget.

Power Loss

Power loss is also a common symptom of a clogged catalytic converter. Whenever your vehicle tries to go uphill, you will notice that your engine will be a bit resistant. If this is followed by an abrupt loss of power, then it is a clear sign there is a serious issue with the catalytic converter.

You will also need to check your fuel efficiency because it is not at its best.

Rattling Noise

Whenever your vehicle has a clogged catalytic converter, you will hear a rattling or a clucking noise. This will happen on a smooth road which does not have rocks or debris. If you ride your vehicle through a rough road and some little dirt enters the engine, it will tend to cause damage to the catalytic converter.

Fumes with a rotten egg odor

Your car is expected to release fumes all the time. Whenever you experience the smell of a rotten egg from the fumes, your car is emitting then know that there is a serious issue with your catalytic converter. This odor is also due to the reduced fuel efficiency of the car engine. Another cause is the imbalance in the fuel mixture.

It is important that you look into these issues as soon as possible. A clogged catalytic converter will result in poor engine performance. It will also cost you a lot of money since you will experience an overrated car mileage.

A vehicle which has a clogged catalytic converter will produce emissions which are more harmful than that of a normal functioning converter.

Tools you will need

A clogged catalytic converter does not have to be fixed right away. To fix it, you will first need to de-clog and clean it. Before you embark on this process, you will need a few things. Here is a list of some equipment which you need for this task:

  • a high-pressure washer
  • a cleaning fabric or cloth
  • helmet/goggles/shades for eye protection
  • wrench

Steps to Fix a Clogged Catalytic Converter

Assemble the materials needed

Before you embark on this task, you need to choose a conducive environment where you will clean the converter. Make sure that the place you choose has enough space for you to work. You will also need to ensure that you have easy access to the high-pressure washer and clean water.

Then, open your engine for the first stage inspection.

Remove the catalytic converter

To carry out an effective inspection, you will need to remove the catalytic converter. To do that, use your wrench. First, loosen and remove the bolts that hold the converter in place.

Ensure that you put the screws and bolts in a safe place because you will need to use them when fixing the converter. Gently lift the converter and put it on stable ground for inspection.

When doing the inspection, check for discoloration and damage. Shake the converter, and if you hear any funny noise, then there’s damage.

Clean the converter

After doing the inspection start to de-clog the converter. Use the clean cloth to wipe off dirt from the surface of the converter. To remove rocks or debris, use the high-pressure washer. Ensure that it has both the inlet and outlet pipes.

Dry the converter and put it back for testing

It is very important you ensure that the converter is completely dry before you reinstall it. You can use the piece of fabric to wipe off excess water. Reinstall it back to the exhaust system. Test the engine.

It is vital that you ensure that your engine is in perfect condition. Whenever you notice that you have a clogged catalytic converter, you need to deal with the issue immediately. This will always ensure that your vehicle is in perfect condition. It will also help you to avert potential accidents.

Frequently Asked Questions (FAQs)

Can I use a fuel additive to clean a catalytic converter?

A fuel additive can only be used to clean a functioning converter and help improve on its efficiency. Normally, you cannot use a fuel additive to repair a failed catalytic converter.

Why should I have a catalytic converter?

Your car needs to be fitted with a catalytic converter for it to be in a perfect working condition. It will also improve on the performance of your engine. You will also be complying with the government emission legislation which requires that every car is fitted with a new cat.

What might cause my catalytic converter to fail?

Your catalytic converter might fail due to several reasons such as road damage which results in the converter being hit by solid objects and also from contamination by using the wrong type of fuel.


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