Symptoms Of A Bad Catalytic Converter: How To Fix One

Catalytic converters, an essential component of your car’s emissions system and intended to last the vehicle’s life, can stop working if they get clogged. The exhaust gases from your car cannot pass through the muffler when this occurs, which is frequently the case for older cars.

That implies that the gases cannot escape from the vehicle’s rear or front vents, resulting in an improper fuel-air mixture that kills the engine. In essence, the catalytic converter “fails” to perform as intended.

Your car’s catalytic converter is a crucial part of the exhaust system that reduces the pollution your gas-powered engine produces. It protects the environment from corrosion by changing the poisonous gasses released during fuel combustion into less dangerous gasses.

But, your catalytic converter could occasionally become clogged, preventing it from carrying out this critical task.

How Do You Unclog A Catalytic Converter?

You are probably looking for a quick fix for the catalytic converter at this stage because you are confident in the condition of your catalytic converter. The good news is that you can clear your catalytic converter in two ways.

Here are some things to keep in mind, though. Please make sure the catalytic converter isn’t irreparably clogged. Also, you want to confirm that it is not damaged. If your catalytic converter is in any of these conditions, you should seek the assistance of a professional rather than trying to fix it yourself.

Once that’s done, you can use these techniques to unclog your catalytic converter.

Here are the method:

1.     To prevent burning, let the exhaust system cool down.

2.     Jack up the vehicle and use jack stands to keep it suspended.

3.     Delete the oxygen sensor(s).

4.     To remove the bolts, use penetrating oil.

5.     After removing the catalytic converter, check it. You should probably stop if you hear a loud rattling because the catalytic converter’s parts are almost certainly broken. You should carry on with the process if you don’t hear anything.

Close up old catalytic converter removing from the engine.

6.     Wash the catalytic converter with a low-pressure pressure washer.

7.     Put hot water and a degreaser on the catalytic converter.

8.     Use the pressure washer’s low setting to rinse the catalytic converter.

9.     The catalytic converter should be reinstalled after drying and draining.

10.     Reinstall the oxygen sensor(s) after the catalytic converter is back in its place.

What Happens If Your Catalytic Converter Is Blocked?

Most people struggle to think of many automotive parts that are more significant than the catalytic converter. Even if you’ve never heard of a smooth-running catalytic converter, you might dismiss it due to its role every time you turn the ignition.

Yet, the catalytic converter’s function is to transform hazardous emissions from your engine into less harmful ones to enhance air quality while, in some situations, reducing pollution and respiratory ailments.

Catalytic converters, first used in most cars in the 1970s, are stuffed with rare materials that transform harmful engine emissions into safer substances for humans to breathe. Problems with your catalytic converter could be detrimental to the functionality and health of your engine.

What Are Five Signs Of A Bad Catalytic Converter?

The only issue is how to detect a faulty catalytic converter. Here are five signs of a clogged catalytic converter:

1.     Your acceleration is awful

One indication that your catalytic converter is clogged is if your car doesn’t accelerate smoothly when you press the accelerator. Decreased engine performance or efficiency should raise a red flag because it’s another indication that there’s exhaust clogging the catalytic converter.

Man driving his car.

When you try to accelerate, if your car jerks or stops altogether, there is probably not enough fuel getting to the engine. A catalytic converter that is clogged may be the root of this issue.

If you address a clogged catalytic converter before it harms other parts of your automobile, you may be able to clean it out, much as you may treat the liver disease if you identify it early enough.

2.     You fail a vehicle emissions test

Because the catalytic converter is a component of your car’s emissions system, it stands to reason that a catalytic converter that isn’t working correctly would cause the emissions test to fail. Vehicle emissions testing is required every year.

The examination will reveal whether the catalytic converter is functioning correctly, which is essential because it’s the central part responsible for clean vehicle emissions. Increased carbon emissions, tainted antifreeze or oil, or any other indicators indicated above are issues that could cause you to fail the test.

3.     Your Service Engine Quick Light Is On

When your liver fails, your body will let you know, and your car’s warning light will tell you when something is wrong. Your automobile will have an onboard diagnostic system that automatically tests the catalytic converter if it was built in 1996 or later, and the odds are strong that it was.

Air-to-fuel ratio sensors that assess whether your exhaust releases too much pollution can turn on the check engine light. Occasionally a malfunctioning catalytic converter breaks due to a failing spark plug or another auto part. Therefore if you suspect a problem, replace any damaged spark plugs and arrange an inspection.

Mechanic changing broken car spark plugs.

4.     Fuel efficiency is not good for you

Have you noticed that your gas mileage has decreased from what it once was? Was it a sudden occurrence? This can be yet another sign of a failing catalytic converter.

Your engine works harder the less oxygen it is given. The more labor it must do, the more fuel it uses. The less energy it uses, the fewer miles per gallon you can go.

5.     Your Car Is Having Trouble Starting

Sleepiness or having trouble getting out of bed in the morning is one sign of liver disease. The same thing can happen to your car with a blocked catalytic converter, making it challenging to start the car quickly. What causes this to occur?

Your car’s engine can stall due to higher exhaust pressure if your catalytic converter is clogged and keeps exhaust gases in the vehicle. Your automobile may have a catalytic converter problem if it initially runs well but then suddenly stalls or sputters.


Like most auto parts, your catalytic converter is subject to wear and tear or environmental factors that make it less effective. Usually, a blocked catalytic converter would make it more difficult for the exhaust system to function correctly.

By removing the converter and cleaning it or washing it while it is still connected to your vehicle, you can unclog the converter and eliminate any interfering carbon deposits. To avoid damaging the converter, use caution when cleaning it. If it’s your first time, ask a trained mechanic to walk you through it.

Avatar photo
About Matthew Webb

Hi, I am Matthew! I am a dedicated car nerd! During the day, I am a journalist, at night I enjoy working on my 2 project cars. I have been a car nerd all my life, and am excited to share my knowledge with you!