Can A Catalytic Converter Be Cleaned?

I used one cup of liquid dishwashing soap and one quart of Harbor Freight heavy-duty cleaner as a cleaner and defoaming agent. "All the other cleaners were a waste of time and money". And a small pond pump and some rubber tubing to circulate the solution through the cats for about three hours each and used the garden hose to get out the residue. Host each cat down with one can of carburetor cleaner. It has worked great for three years now! Unless the internals of cats turn loose and renders them unusable all you have to do is wash them out they don't go bad they just get dirty on the inside.

I followed Scotty's recommendation with the lacquer thinner to a tee, and it worked beautifully. Many people are not running their engines for 150 miles at high speeds and running that tank completely out immediately and then refilling it with a fresh tank and running it some more. Not doing these will cause the problems.

The cleaning videos, like Scotty, said, "...try cleaning the catalytic converter first to clear the p420 code." It's easy and cheap. Then they mentioned, if those techniques don't work, do the bulk work (remove converter) and bulk spending (replacing coverter). What is wrong with trying? It worked in many cases because most converters don't get to that state before throwing a code and the light amount of carbon dust in the c.c. will burn and blow out.

The soap is definitely making a difference. Water only wouldn't get into the hydrophobic fine carbon. The soap breaks the surface tension and helps break up the fine carbon particles. Just my 2c.

Thanks Fifties Kid! Your thoroughness and patient effort is much appreciated.

The cover is aluminized (aluminum coated steel), which is why the Sodium Hydroxide was dissolving it; you can see that the finish on the heat shield looks much more dull after being soaked in it.

My 2005 jeep TJ was showing the same codes. I put the scanner on it and the o2 sensors were behaving the same way. Thanks for the help. That confirms my suspicions of a shot converter.

That oxygen storage test is gold! I learned something.

Lacquer thinner worked great on my truck. I poured it in the gas tank. Cleared my P0420

Thanks for sharing this buddy, it's nice to see that people still post real things like when something doesn't quite work out. You win some you lose some. But if you don't try these things you'll never know if it'll work.

Excellent tutorial. Camera work, editing & narrating is smooth & entertaining.

I am pretty sure he just had a bad downstream O2 sensor, seen it before and he never really tested to see if replacing the downstream sensor would have fixed the issue. Never used laser temp reading on upstream and downstream, yes the propane test showed that both sensors reacted, but still say a bad downstream could account for that.

Very intensive practical tests and couldn't agree more on the drive cycles. The mil light governs the result, on, grand off,trouble. Increasing the engine speed shows the cat in its true colours.

I took off my o2 sensors before the catalytic converter and blew a can of that Seafoam Spray Top Engine Cleaner and Lube used about half each side. It cleared my codes and I haven't had them come back yet. It's been about 8 months since that treatment. I figured that spray is made for specifically for motors and it blows through the catalytic converter anyway so can't harm to much and if it does I'll just cut them out until I find an affordable one that is reliable. Luckily it seems to have worked enough to buy me another year to find one. I also soaked my o2 sensors in berryman b12 for like an hour which cleared 1 of the 2 codes related to that. This guy is experimenting with the CaT he plans on using when he should've used a dummy one just to test what effects it has on the metals. For all I know I could've just melted all the metals and blew them out my tail pipe but hey no codes right haha.

Thanks for the time and the tests.

Thank you so much for doing this! Much appreciated. I also live in socal (downey) I think i've seen you at pick your part!

I really appreciate this kind of video in an area where there is so much hype and misinformation. Here, there is a thoughtful methodology and an honest attempt to test. It's important to note that this was a single data point and it doesn't cover all cases but it certainly confirms the negative - i.e. not all failures can be fixed by cleaning.

I'm so happy to watch all the procedures done scientifically - you made an hypothesis, tested it and proved it and used reliable evidence tool and scientific method ... applauds

“It’s not the soap” and “water bubbles “ had me dying

Very informative video. I appreciate allthe details of how it works and how to test it properly not just looking and saying its plugged. I could see that this one didn't look pkugged but still explained a lot of why you may be getting a code and how to diagnose that without putting in a downstream spacer.