Can Catalytic System Cleaners Work?

[doitmyself]

Can an intermittant P0420 code be caused by fouling in the system and is it possible that a cleaner added to the gas can correct this??

Here's a questionable review of some of the products: https://www.carbibles.com/best-catalytic-converter-cleaner/

 

[Jimzz]

Rarely will they help as them being dirty is usually not the issue unless you have been running very rich for a while. Its generally the metals have worn out and there is not enough to function anymore.

 

[demarpaint]

They're hit or miss, occasionally they work. A friend of mine used it to sell his Expedition, it kept his CEL off long enough for him to get rid of it.

 

[Trav]

Call me skeptical but if you need to change the cat anyway consider it a hail Mary and try it.

 

[StevieC]

If the catalytic is right on the edge setting codes occasionally they might have a benefit but if the cat is done then no but even then the odds are against you.
We used to emission test at my dads shops and we would have people try everything like these fuel additives and an Italian Tune-up before spending the money on cats or EGR valves when it would fail again.

 

[SwampSurvivor]

For $3 you can get an anti fouler.

Significantly more effective at getting rid of that CEL than anything else. Now if you're getting sniffed ...

 

[Nickdfresh]

I wouldn't bother with Cataclean, used it twice and both times it was equally useless. I do think CRC is a good product though, it's a very strong FI cleaner if nothing else...

 

[Ct70NuT17]

I have used the CRC "cleaner" they sell at wally world and it kept the CEL light off long enough to sell the POS down the road. For less than 10 bucks I say .. why not try it!

 

[anndel]

Cat converter getting clogged or fouling O2 sensors. I would check the easiest thing first - O2 sensors. If all ok then drop the cat converter to see if clogged. All you have to do is look in one end and hold it up to the sun or shine a light in the other end and if not clogged, you'll see all the way through. If clogged, you won't see anything or maybe a small dime sized light.

Those cleaners are a waste of money and most times won't work.

 

[Wolf359]

Originally Posted by anndel
Cat converter getting clogged or fouling O2 sensors. I would check the easiest thing first - O2 sensors. If all ok then drop the cat converter to see if clogged. All you have to do is look in one end and hold it up to the sun or shine a light in the other end and if not clogged, you'll see all the way through. If clogged, you won't see anything or maybe a small dime sized light.

Those cleaners are a waste of money and most times won't work.


They don't call them hope in a bottle for nothing.

 

[JTK]

You never know. If it's just a matter clearing some deposits out of the way to expose just enough good catalyst to satisfy that downstream O2 sensor, you're in business.

 

[doitmyself]

What about the O2 sensors? Can these cleaners "fix" them if they are just starting to foul up?

FYI, I am asking on behalf of someone else.

 

[dogememe]

Even if it works 10% of the time, awesome! I used CRC "Guaranteed to Pass" in a 97 Suburban once that had been driven a whole bunch with a stuck open injector misfire... it passed the smog test (which includes an OBD check and actual sniff test for older vehicles in California), and about a month later it threw a P0420 so I'm happy with the product.

 

[Audios]

Ive had luck leaving them in 4th on the highway (whichevers below overdrive) and getting them super hot, along with a fuel injection cleaner in the tank. Give it 50 miles in 4th and went right through. I dont know the long term results as to how long the light was off, but it worked for NJ state inspection.

 

[PandaBear]

Originally Posted by doitmyself
What about the O2 sensors? Can these cleaners "fix" them if they are just starting to foul up?

FYI, I am asking on behalf of someone else.


O2 is only around $30 shipped from RockAuto (assume you have an old car since you are concerned about O2), it is easier to just change it than to try out a $20 bottle of cleaner.

Most of the worn out O2 I see have white or grey deposit, likely poisoned, instead of dirty.

 

[01rangerxl]

Originally Posted by Nickdfresh
I wouldn't bother with Cataclean, used it twice and both times it was equally useless. I do think CRC is a good product though, it's a very strong FI cleaner if nothing else...


My 02 Ranger had a restrictive cat failure a few years ago and Cataclean was indeed totally useless. Literally no change. Put a new direct fit y pipe converter assembly on and that fixed it.

 

[Vikas]

Once again changing O2 sensor will only make the P0420 come on stronger than before but you need to learn this hard way on your own.

 

[MaximaGuy]

Originally Posted by doitmyself
Can an intermittant P0420 code be caused by fouling in the system and is it possible that a cleaner added to the gas can correct this??

Here's a questionable review of some of the products: https://www.carbibles.com/best-catalytic-converter-cleaner/



The P0420 is the most overloaded code on the vehicles, it never ever points to the root cause.
The code needs to be changed to actually detail which one is giving the error, O2, cats, plugs, engine running hot (trust me this is a cause, needing comple cooling replacement) etc etc.
Its more hunting through the most common areas before you can ever root cause the fail.

 

[spasm3]

I'd spend my money on the anti foulers, rather than the bottle. Run that until you get the cats changed. Assuming of course that the plugs wires and things that cause a cat to go bad are replaced.