How to Clean a Catalytic Converter (Without Removing it)

A catalytic converter is collecting a lot of particles and other stuff coming out from the engine. This means that it can get clogged and need a cleaning. Here's how to do it

How To Clean A Catalytic Converter

Are you struggling with the P0420 code and want to clean your catalytic converter, but realize that it’s a lot of work to remove the catalytic converter, and you want to do it without removing it?

Then this article is for you. We will discuss how to remove the catalytic converter without removing it from your car to get the best results, and you may save a lot of money by doing so.

If you want to learn more about the P0420 code before cleaning it, you can check our article about this here: P0420 code.

Things to consider before starting

There are some things that you have to consider before trying to clean your catalytic converter. In a lot of cases, the parts inside the catalytic converter will become loose. If this is the case, you can’t repair your catalytic converter without removing and replacing it.

1. Too clogged

If your catalytic converter is so clogged that the engine will not run, you have to remove the catalytic converter and either use special tools or replace the whole catalytic converter.

2. Check/listen for loose parts

You can take a rubber hammer and hit your catalytic converter carefully, and listen to ascertain if there seem to be any loose parts inside it. If you can hear loose parts, I recommend removing and inspecting the catalytic converter because the loose parts could come even looser and clog your exhaust pipe totally, which may cause your vehicle to stop while driving.

Clogged Catalytic Converter
A clogged piece from the catalytic converter. If you find a piece like this in the exhaust system, it’s time to replace the catalytic converter.

3. Purified catalyst

Remember that your catalytic converter may have been cleaned inside, and the parts inside it may have blown out from the exhaust pipe. This can be tough to see without removing it, and if you suspect this, remove the catalytic converter and check it.

4. Oil consumption

Your catalytic converter may have got clogged due to internal oil consumption, caused by oil entering the cylinders and getting combusted and burned inside the hot catalytic converter.

If this is the case, you should always repair the internal oil leak before using this cure, as it may only work for a short time until the catalytic converter is clogged again. Common symptoms of an internal oil leak are clogged crankcase ventilation, broken valve seals, or piston rings. Always check the crankcase ventilation first.

How to clean your catalytic converter without removing it

If you have checked and listened carefully for any loose parts inside your catalytic converter and your are sure that the car is not burning oil, follow these few steps to clean your catalytic converter:

Total Time: 10 minutes

Step 1. Get Oxicat Catalytic converter cleaner

Oxicat Catalytic Converter Cleaner

The easiest way to clean a catalytic converter without removing it is by using a catalytic converter cleaner product. One product we recommend is the OXICAT – Oxygen Sensor & Catalytic Converter CleanerIr?T=Askamastermec 20&Amp;L=Am2&Amp;O=1&Amp;A=B01Lfxtae2.

You can find more of these products in our guide: Best Catalytic Converter Cleaners. You tap it into your fuel tank, and it does not matter if you have petrol, diesel, or hybrid car. This will help clean the catalytic converter; it will also clean your O2 sensors and the whole exhaust system.

Remember that this product will not repair mechanical faults inside your catalytic converter if it’s cracked, broken, or too clogged. This is a cleaner for a slightly clogged catalytic converter that lost its power due to time.
Of course, you can also use other brands of catalytic cleaners, but this one has worked best for me so far.

Sale
Oxicat Oxygen Sensor & Catalytic Converter...
1,099 Reviews
OXICAT Oxygen Sensor & Catalytic Converter...
  • Safe and effective for all petrol...
  • Engineered to clean the entire exhaust...
  • OXICAT is activated when the catalytic...
  • Proven safe and effective by the Pros,...

Step 2. Pour the Catalytic converter cleaner into the fuel tank.

Shutterstock 469192094

Check the cleaner’s manual and pour in the exact amount of cleaner into the fuel mentioned in the manual. Ensure that you are using the required amount for your car type and engine, so you are not using too much of the product – this can cause even more damage to your catalytic converter in some cases.

Step 3. Take your car for a drive

Drive Car E1614206004661

Drive your car a couple of miles to see if your car runs better than before. You can also try to drive your car at high RPM’s over 3000 for a long distance to get the catalytic converter really hot to burn out the clog inside it.
Always keep an eye on the coolant temperature though to make sure that you are not overheating the car.

Sale
Oxicat Oxygen Sensor & Catalytic Converter...
1,099 Reviews
OXICAT Oxygen Sensor & Catalytic Converter...
  • Safe and effective for all petrol...
  • Engineered to clean the entire exhaust...
  • OXICAT is activated when the catalytic...
  • Proven safe and effective by the Pros,...

The Oxicat did not work for me, what to do now?

If you tried the Oxicat catalytic converter cleaner, but the problem still persists, there is not much more to do than removing the catalytic converter to inspect it and to make sure it looks okay. Remember that there can be other causes of the P0420 trouble code like faulty O2 sensors or exhaust leaks and the problem may not be in your catalytic converter.

Removing the catalytic converter is often quite easy on most cars if you can get the rusty bolts loose. In some cars, the catalytic converters are installed directly on the turbocharger, and in these cases, the removal of the catalytic converter may be more difficult.

If you still think that your catalytic converter is clogged and looks okay while inspecting it, you can try to clean it in a bath with water and lacquer thinner. This does sometimes work, and it may save you some money.

Check this link for Amazon’s version of lacquer thinner:

Lacquer Thinner [Na-Ltr128], 1 Gallons
503 Reviews
LACQUER THINNER [NA-LTR128], 1 Gallons
  • Package Dimensions: 14.5 L x 11.25 H x...
  • Package Weight: 36 pounds
  • Country of Origin : United States
  • Part Number: NA-LTR182

If you tried both the Oxicat cleaner and lacquer thinner, and you can not see any visual signs of damages, but the problem still insists – There is no option other than replacing the catalytic converter.

You should also check for other problems – it might not be the catalytic converter causing your problem.

Catalytic converters are often expensive, and this is because there are noble metals inside them that cost a lot to produce.

Written by:

Magnus is the owner and main author of MechanicBase. He has been working as a mechanic for over 10 years, and the majority of them specialized in advanced diagnostics and troubleshooting. Certified Automotive Diagnostic Technician.