Symptoms Of Clogged Catalytic Converter And How To Fix It Properly?

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You know your car of being oil efficient or at least doesn’t need to feed the tanker like your neighbors and co-workers. But recently, the car is giving poor mileage.

Don’t worry; it is not always that the engine is malfunctioning or the exhaust system isn’t working properly.

The catalytic converter might be the culprit behind your car’s being malfunctioned. But you don’t need to worry about replacing it. There are tons of people having this problem, and they fix it by themselves just by following expert advices.

In this article, you will know pretty much everything about catalytic converter and ways to fix a clogged one.

What Is A Catalytic Converter?

Did this thought ever come to your mind that it’s a part of your car’ exhaust system? The engine emits harmful gas to the exhaust chamber, and before the release, the gas has to go through the catalytic converter.

It changes the harmful properties and releases to the surrounding making it less harmful for the environment.

What Are The Symptoms Of Clogged Catalytic Converter?

1. Engine Misfiring

When the engine misfires, it overheats the exhaust system. And whenever the exhaust is overheated, there is a high chance of catalytic converter to be melted. This melted catalytic converter results in clogging.

Also, extremely rich fuel mixture in the tank causes ignition and allows raw fuel to enter in the converter. It melts the catalyst components too.

2. Loss Of Power During Accelerating

One of the most common symptoms of a clogged catalytic is to lose power while accelerating or going uphill. Often, the mechanics misdiagnose this cause. You can assure yourself by doing a simple test. You will need an assistant for that.

Ask your assistant to hold rpm at between 1800-2000, and you push the exhaust with the hand from behind the tailpipe. If there is hot air flow from the exhaust, the converter is clogged for sure.

3. Overall Poor Engine Performance

If the converter clogged, you will notice a degradation in overall engine performance. It happens when a failing converter creates back pressure, it affects the engine and prevents it from running smoothly. Your car feels like shaky and sudden burst of pressure stalls the engine while driving.

4. Degraded Exhaust System Performance

You can also assure whether the converter is malfunctioning or not by observing the behavior of the exhaust system. If the performance of exhaust system degrades, it means there is something wrong with the converter. This problem will decrease oil efficiency as well.

Also, the exhaust system sounds strange when you start the engine.

5. Distinct Rotten Smell

When the catalytic converter gets clogged, it gives off a distinct smell similar to a rotten egg. This will indicate that there is Sulphur in your catalytic converter. Sulphur forms because the clogged catalytic converter cannot catalyze pollutants properly

6. Increased Emissions

When a converter fails, it reduces gaseous emission. An extreme level of carbon emission indicates the converter is not in a good state. If the proper attention is not given in time, it will damage the entire exhaust system.

7. Dashboard Lights Turns On

When your dashboard lights turn on, it’s a tell-tale sign that your catalytic converter is clogged. Clogged catalytic converters can trigger your sensors that are there to detect any emission issues.

Hence, why it’s useful to check your car’s dashboard if you think your catalytic converter is clogged. However, if you are driving a really old car, it works differently. Old cars usually have diagnostic systems that let you know if there are problems with your car.

If you observed your light comes on when the engine overheats, then your catalytic converter may have some problems. However, the lights turning on doesn’t mean your catalytic converter is clogged all the time. It’s just an indicator that there is something wrong with your car engine.

How to Check for a Clogged Catalytic Converter

1. Fuel Vapor

You can diagnose the converter by doing a fuel vapor test if your car has a carburetor. First, you need to remove the air cleaner and then ask your assistant to torch the carburetor intake. If you see any cloud of vapored fuel, then without a doubt your converter is clogged.

2. Vacuum Test

The vacuum test is another way to check if your catalytic converter is clogged. Here’s how you can do the test:

  1. Set your car transmission to park or neutral depending on the type of your car. Afterward, apply the parking brake.
  2. Next, attach the vacuum gauge to a direct vacuum line. The attachment is similar to that of a direct intake manifold port.
  3. Start the car and let it sit idle until it reaches its regular operating temperature. The vacuum gauge should measure around 18 and 22 in-Hg under the regular operating temperature.
  4. Maintain your car’s speed around 2500 – 3000 rpm as you watch the vacuum gauge. You can ask for assistance if needed. The reading should drop a little before it returns to its previous level in a matter of seconds. When it takes too long for the reading to return to its previous level, then you have a high probability of a clogged catalytic converter.

3. Back Pressure Test

You need to have a back pressure gauge in order to perform this test. You will be mainly checking the exhaust system of your car. Here’s how to do the Back Pressure Test:

  1. Detach the front oxygen sensors from your car
  2. Replace the front oxygen sensors with the back pressure gauge
  3. Finally, start your car and observe the reading from the back pressure gauge. When the reading is anything between 0 – 3 psi then it’s normal. This remains true even if you increase the speed to around 2500 rpm. When the reading is around 8 psi or more, then your car has a clogged catalyst converter.

4. Temperature Test

In order to do this test, you will need an infrared thermometer or a kitchen thermometer. To conduct the test, follow these steps:

  1. Start your car and let it stay idle until it gets to regular operating temperature. You can drive it around to quicken the step.
  2. Make sure your car is in a flat area
  3. Set your car transmission to park or neutral. This will depend on the type of car you own.
  4. Observe and write down the temperature reading of the inlet pipe. This pipe connects to the front of the catalytic converter and you may need to raise your car to accurately do it.
  5. Do the same reading of temperature for the outlet pipe. This is the pipe that connects to the rear of the catalytic converter. If the front temperature is around the same temperature level as the back temperature, then you have some problems with your catalytic converter.

How To Fix A Clogged Catalytic Converter?

If the term “catalytic converter” seems unfamiliar to you, there’s no reason to worry. I have never heard this term until today, and I’m assuring you that unclogging a catalytic converter won’t be too difficult for you.

Method 1: Cleaning Method

To follow this method, you will need;

  • Wrench
  • Cleaning cloth
  • Goggles, shades, and helmet for eye protection
  • Pressurized washer aka high-pressure washer

1. Choose A Suitable Location And Necessary Materials

Before starting the fixing, choose a suitable location that has enough space for work, access to clean and pressurized water. Park your car on a well-lit flat surface. Open the hood and raise the prop rod and keep the hood open.

Wear protective eyewear before jumping to the next step.

2. Remove The Catalytic Converter

First, you need to remove the catalytic converter. Remove the bolts with a wrench that are securing the converter. After loosening the screws, place them in a secure area or a box because you will need them again.

Now, gently lift the converter from the exhaust system and place it on a stable surface for further inspection.

3. Inspecting The Catalytic Converter

Inspect the converter and look for any visible damages. You also need to shake the converter and see if you hear any unusual noises from it. If there is any damage, it will certainly make noise. In that case, if you find any damage, consider disposing that part and replace with a new one.

Now, check through the passageways to see if there are any partial or total blocks. If you find the passageways are blocked, then it is recommended to replace only that part.

In addition to that, if the converter is clogged the whole system and completely melted off, you need to change the entire system.

Note, if the police find your exhaust system isn’t working properly, you are most likely to be fined for it.

4. Cleaning Tips of a Clogged Catalytic Converter

After you have replaced the damaged parts, now you are good to start the de-clogging process. The converter consists of filth due to the bad fuel injection. In this case, you need to rev the exhaust system and push or melt out the filth inside.

Similarly, if you find the passageways are partially blocked, cleaning would be enough for the converter to work like before.

Use a high-pressure washer to push out all the tinny elements, rocks or debris that are blocking the passageways. Do not forget to use high-pressure water into the inlet and outlet pipes as well.

If the highly pressurized water isn’t enough to clean your car’s converter, then make a mixture of water and degreaser and soak the entire converter for few minutes.

5. Let The Converter Completely

Before putting the converter into the exhaust system, let it dry completely. Use a dry cloth and pat away excess water and droplets to make the drying process faster.

When it is dried, now gently put back the converter into the exhaust system and screw the bolts properly using a wrench.

6. Test Drive

After doing all the procedure, now you can go to a drive to test whether the fixing has improved the car’s performance or not. If the problem persists, do not be late to seek professional help.

Method 2: Taking The Car To The Highway

If your catalytic converter is clogged with minor issues, then taking the car to a highway will do the trick.

Drive the car on a highway and drive at a speed limit for two miles. Push down the brake pedal to reduce the speed. Repeat the process and if you find the performance of your car is increasing, congrats on successfully unclogging the catalytic converter without any hassle.

Frequently Asked Questions (FAQs)

How Long Does a Catalytic Converter Last?

Usually, a car or truck’s catalytic converter typically last about 100,000 miles. However, there are several reasons why catalytic converters aren’t able to last that long in reality.

What Causes a Catalytic Converter to Fail?

There are various reasons why a catalytic converter fails.

  • When the engine is out of tone
  • Excess fuel in the combustion chamber cause fuel to enter into the exhaust system causing a converter to fail
  • When oil or antifreeze enters into the exhaust system, it blocks the air passages of a converter
  • Deteriorated spark plug causes unburned fuel entering the exhaust system and melts down the ceramic catalyst.
  • If the oxygen sensor doesn’t function properly, it leads to incorrect readings to exhaust gases which trigger the catalyst melting down
  • Rock debris on the road strikes into the converter and cause catalyst fracture

How Long Can You Drive With a Bad Catalytic Converter?

Driving with a malfunctioning catalytic converter isn’t always dangerous. If the key parts of the converter are still plugged, you can drive the car as usual. But if the case is complicated, the converter will completely fuse overtime, and it needs to be replaced asap.

To Conclude

It is not that difficult to fix a clogged catalytic converter. Taking a quick and effective step will keep your engine in good condition. Delaying the fixing process will affect the engine’s overall performance.

If the problem is too difficult to fix it by yourself, you may need to visit a professional mechanic.

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