Catalytic Converter

How to Clean a Catalytic Converter without Removing it

In Engine by 26 Comments

Are you struggling with the P0420 code and want to clean your catalytic converter, but you 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 out 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, and if this is the case, you can’t repair your catalytic converter without removing and replacing it.

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.

Check/listen for loose parts

You can take a 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
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.

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.

Related:  PCV Valve Symptoms, Location & Replacement Cost

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 to your catalytic converter to make sure there are no loose parts inside it and the catalytic converter is not too clogged, there are a few steps you can do to clean your catalytic converter.

Total Time: 10 minutes

1. Get Oxicat Catalytic converter cleaner

Oxicat Catalytic Converter Cleaner

The product that you can use is the OXICAT – Oxygen Sensor & Catalytic Converter CleanerIr?t=Askamastermec 20&l=Am2&o=1&a=B01Lfxtae2. You tap it into your fuel tank, and it does not matter if you have petrol, diesel, or hybrid car. This will help not just to 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 the catalytic converter which may have run with some oil burn before.

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,...

3. Take your car for a drive

Drive Car

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. Remember to check that there is no oil or other fluids in your catalytic converter that could ignite it. Also, check the coolant temperature of your car at all times, to make sure it’s not overheating.

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 car’s, the catalytic converters are fitted directly to the turbo, and in these cases, the removal of the catalytic converter may be more difficult. Let an automotive workshop do the job for you if you are not sure how to do it.

Related:  Fuel Gauge Sensor Symptoms & Replacement Cost

If you still think that your catalytic converter is clogged and it 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:

  • Thins lacquer thinner and epoxy
  • Medium dry-rate
  • VOC Compliant, per CARB

If you have tried to clean it and diagnosed the catalytic converter correctly to make sure it’s the parts that are damaged, there are no other choices than replacing the whole catalytic converter. Catalytic converters are often expensive and this is because there are noble metals inside them which cost a lot to produce.


  • Tap on your catalytic converter with a hammer to make sure there are no loose parts inside of it.
  • The cleaner will not repair cracked, broken or excessively clogged catalytic converters.
  • If the catalytic converter cleaner did not work for your vehicle, check all other related parts to make sure they’re not damaged and remove the catalytic converter to inspect it.
  • You can clean your catalytic converter in a bath of lacquer thinner if you are removing it.
  • Catalytic converters are often expensive due to the noble metals inside them.

Have you tried this method before to clean a catalytic converter? Let us know how it worked out for you by commenting  below! If you have any other car questions you are welcome to ask them at our homepage.

26 thoughts on “ How to Clean a Catalytic Converter without Removing it ”

  1. My car runs great TSX 2011 162,00 miles a recall at 125,ooo miles pistons timing chain etc because of too much oil consumption. Now that code comes on then goes off??

    1. Author

      Yes, there is most likely oil in your catalytic converter. The problem may disappear if you continue to drive it. Drive it hard to burn out the oil from the catalytic converter. In the worst case scenario, you may have to replace it.

      Of course, you can also try an additive to clean it while driving.

  2. Have a diesel car but don’t drive far these days-what should I do to protect the catalytic converter

    1. Author

      You have a DPF filter in your diesel car. It’s important to not only drive for short distances while you have a DPF filter. Over time when you are driving the car warm, the DPF filter will clean itself with a regeneration. However, the engine has to be warm for this function to work properly.

      There are also additives for DPF filters if you are worried 🙂

    2. Can you clean your cat by spraying sea foam inside by taking off the sensor?

  3. Hi I’ve changed my diesel car’s turbo charger recently but there is still no power it’s really weak and when I accelerate or drive uphill it makes a sound like whistling. Also, when I turned my heating on a smell coming from the engine bay get in the cabinate it’s like oil burning smell.
    What could be the problem?!

    1. Author

      I would check for any boost pipe leaks. The best way is to use an EVAP smoke machine, but you could also let a friend rev it up while you are listening or applying soap on the pipes and checking for bubbles!

      1. My 1993 Subaru legacy won’t pull going up a hill until I find a sweet spot on the gas pedal then it takes off what gives

  4. hello . my car is suzuki sx4 2007 . defect my car in p0420 code. do i can wash the catalytic converter by spray cabreater cleaner or cook cleaner liquid

    1. Author

      You can try to clean it with catalytic converter cleaner as mentioned in the article, I do not recommend using anything else because I have not tried it and I can’t recommend things that I’ve not used with success. It does not always help but it’s often cheap to try it. If the code still comes back several times after the wash, you have to replace the catalytic converter.

    2. Het some berrymans injector intake valve cleaner like 4 bucks…disconnect a fat vacuum hose and but a little hose on it to let the car still run..take the vacuum hose and let it slurp up the injector cleaner for about 3/4 of the bottle..takes a long time it slow or car will die.the goal is to get it passed the valves a bit.and into the cat..the extra fumes and cleaner will burn hotter then normal and burn the cat and try and loosen up the junk..most time turn to ash.and blow out.or set back farther in the honey combs..and the rest of the bottle pour in the intake.then one it your tank..and take it for a long hard chance at cleaning out.will throw a 420 code tho..that means it made it where it needs to be….

      1. I have a 08 Ford Explorer 4×4 XLT with 177,000 miles on it and it jerks when I stop. And it has been turning off on me while driving multiple times.
        I’ve change the amf sensor, battery and throttle body unit. What could the problem be?

  5. Hello, I have an automatic diesel Korean Hyundai Santa Fe 2005, and after taking it for gear box and turbocharger change the car doesn’t accelerate as it used to, especially when ascending a ramp or hill, what could be the problem? Please I need help

  6. I have a 2013 JX35 Infiniti that they say I need to replace my catalytic converters to the time of $2200. Is it possible that it is just CLOGGED, and can I use the catalytic cleaner to see if that will work?

  7. Hi, I’m having a hard time trying to get my check engine light to go out NOW I had the PO420 code and another code keep coming up I got a diagnostic and the paper work said the was nothing wrong with the catalytic converter but the code keep coming up on the machine and the light won’t go out I had one of the codes fixed but they fixed the wrong one they fixed the one under the truck but it was the one on top so the guy at the place told me to use cataclean to try and clean out the converter he told me to fill it up drive it high speed and run the gas out if the light didn’t go out to fill it up again run all the gas out so my question is even thou I put the cataclean in my truck ran out one tank of gas should I try what oxyclean or just fill up the tank and ran the second tank of gas out? I’m so confused and frustrated. Oh and is there a way to know if a cat. Converter is bad before I buy it. One more question can a 2001 Silverado catalytic converter fit a 2003 chevy tahoe?

  8. O have a 04 ford Taurus and changed the fuel filter,egr vale,egr valve sensor but the plastic egr sensor and 2 little hoses keep melting. I took it to get it tested and thats all pops up on the test. I don’t know why it keeps melting them things

  9. Hello,

    We have a 2009 Hyundai Santa Fe – live in south Florida – and it has been running rough on start up. It was taken to a repair shop yesterday and we were told the catalytic converter needs to be replaced. However, I found your information on Oxicat and we would like to try it. Is one use of it recommended, or is it something that should be added every time we fill our car with gas? Is the entire can used at one time?

  10. I have an 09 Honda Accord and the check engine just came out with a p0420 how can I tell is catalytic converter or just a sensor

  11. Hi.
    Can you still drive with a bad catalytic converter? I don’t want to put my kids in danger.
    Can I try oxicat if i don’t know if the cat.con. needs replacing?

  12. I have a 2004 Ford Expedition and I just replaced the motor. The truck was running fine before the motor went out,now after the new motor is in the truck seems to lack power and I’m thinking that the catalytic converters are clogged due to seeing lil chunks that look like wood laying behind by the tail pipe. What can I do?

    1. Hey bud..shake the tail pipe.and exhaust if you can..can hear a rattle..not good..those wood chips sound like the element inside your looks like a bee hive..kinda is falling apart:( need a new one

  13. I have 2007 Nissan pathfinder. Bad smell from exhaust and rattling sound.

  14. I have 07 mit. Eclipse 4cyl manual that had timing belt go out and had replace engine valves, afterwards now will make 3rd exhaust manifold gasket having to replace. Believe Cadillac converter may be causing this to happen. Was hoping for any alternative to resolve problem w/o replacing Cadillac converter. Any advice greatly appreciated.

Leave a Comment