If you’re experiencing slow acceleration and detecting a rotten egg odor, you could have a clogged catalytic converter. Instead of spending a fortune on a replacement, consider attempting to clean it first.
Find out the safest and most efficient way to clean your catalytic converter at home. We will explain two distinct approaches: a simpler one and one that is more effective.
Cleaning Method #1 (Without Removing It)
The first cleaning approach does not need you to take out the catalytic converter, scrub it, or get your hands dirty. Instead, you will save money since you won’t have to buy additional materials. Also, this method removes the deposits from the fuel system, oxygen sensors, and exhaust system as well.
To be fair, if your catalyst honeycomb is broken or your exhaust system is severely dirty, this approach will not work.
If you would like to determine if this cleaning method applies to you, use a mallet or wrench to tap the converter. You should hit it hard enough to rattle it, but not so hard that it becomes dented.
Hearing rattling noises from the inside means you have broken parts or heavy sediments. The only way to solve this is to remove and clean the converter.
As long as you do not hear any unusual sounds, continue with the steps below:
- Buy enough fuel and catalytic converter cleaner. Purchase fuel from a gas station and also buy a catalytic converter cleaner that is suitable for your engine. Not all cleaners are made for diesel or gasoline engines. Some work for both, while others specialize in one.
- Add the appropriate fuel into the tank. Instructions on how much fuel per volume should be added and what the fuel-loss ratio should be will be provided on the label.
- Take a drive. After adding the solution, start the engine and drive your vehicle. The exhaust will circulate the system, and the cleaner will be distributed to clean the exhaust system. The label should indicate the duration necessary to achieve optimal results.
To maximize the temperature of the catalytic converter, we recommend driving with the RPM over 3000. The elevated temperature will eliminate build-up and clogs within the converter’s core.
If your vehicle has an automatic transmission, switch it to “Sport” mode. If you drive a manual, hold onto each gear a little longer before moving to the next one.
Avoid overheating by checking the vehicle’s temperature gauge periodically. If the cleaning process works, you should experience less exhaust smoke, faster acceleration, and reduced engine misfire occurrences.
Cleaning Method #2 (Removing It)
You will need to take the catalytic converter out if the first method doesn’t work, as you need to do some more serious cleaning on the catalytic converter exhaust system.
This is quite simple as long as you have the proper equipment and understanding, and, as with other exhaust components that are exposed to the environment, the stubborn bolts are always the hardest part of the job.
The following items are required from the start:
- Automotive degreaser
- A big container to soak the converter
- Penetrating oil such as B’laster or WD-40
- Floor jack
- Jack stands
- A wrench that fits the bolts of the converter (preferably an impact wrench)
- Oxygen sensor wrench
- Pressure washer
Once you gather everything, perform the following steps:
- Allow the exhaust system to fully cool before you start working on it.
- Raise the car until you can comfortably slide under it. Always use jack stands to keep the vehicle supported.
- Unscrew the oxygen sensors with the oxygen sensor wrench.
- Locate the catalytic converter and apply penetrating oil to help loosen the bolts. If the catalytic converter is bolted or welded on or attached to the turbo, have a professional mechanic do the work.
- After unscrewing the bolts, take the converter out and check it. If it rattles loudly, it’s broken internally, and you need to get a new catalytic converter.
- If there is barely any rattle, remove all loose debris from the exterior of the converter and then clean the interior using a pressure washer on a low setting.
- After cleaning the inlet and outlet pipes with a pressure washer, pour hot water and a degreasing solution into a container.
- Allow the converter to soak in the hot water and degreaser solution for one hour at most.
- After soaking, blast the unit with a pressure washer on low and let it drain until dry.
- After everything is dried, put the system back together, reinstall the oxygen sensor(s), and take the vehicle out for a drive to see if the issue improves.
Will Cleaning Work All The Time?
When cleaning the catalytic converter with the two suggested methods fails to show signs of change, it is best to replace the converter. Although changing it is costly, it maintains efficiency and legality for the car.
Besides cleaning, if there is an oil or coolant leak inside, then this repair may not resolve the issue. Those spaces will continue leaking into the hot converter, leading to the formation of thick smoke and soot, which clogs the system. Leakage can be caused by breaks in valve seals, damaged piston rings, or a blocked crankcase ventilation.
What NOT To Do
To protect your catalytic converter while cleaning, do not:
- Do not let the component soak in bleach or grout-eating gel, or other corrosive substances that may harm the catalyst.
- Do not pour paint, lacquer, or thinner in the gas tank.
- Do not use a catalytic converter not suitable for the specific vehicle make or model.
- Do not attempt to saw off a welded catalytic converter without professional help. This could result in damage to the vehicle, injury, or both.
Use these techniques to help you learn how to clean a catalytic converter yourself. If there is anything you would like to ask, feel free to contact us.
What Causes a Catalytic Converter to Clog?
Catalytic converters capture carbon buildup over time, resulting in decreased efficiency. This typically happens when running a rich air-fuel ratio for too long. In such cases, your vehicle will show symptoms like:
- P0420 error code indicates a catalytic converter problem has been detected
- Exhaust smells like rotten eggs
- A decrease in the engine’s performance and acceleration
- Black smoke emissions
- High temperatures from the bottom of the vehicle
Generally, cleaning the catalytic converter removes the P0420 code along with the rest of the symptoms. If you wish to do it on your own, there are two ways to clean it. One method involves removing the converter, and the second one does not.
Before jumping to the steps on how to clean a catalytic converter, you can avoid these causes of catalytic converter clogging:
- Driving over bumpy roads is known to break the ceramic catalyst honeycomb that is contained within the catalytic converter. The broken pieces can clog the system.
- Oil or antifreeze may seep into the exhaust system. Upon heating, these leaks will turn into dense exhaust smoke and residue, which obstructs the system. Due to the age of the vehicle, broken seals, irregular servicing, or adding excess engine oil, a leak may occur.
- A catalytic converter won’t reach burning temperatures during short trips, which means engine hydrocarbons that enter will accumulate instead of being burned, eventually leading to a clog.
Is it possible to clean a clogged catalytic converter? Yes, and we are here to show you two DIY methods that will help you save time and money.