Stock Catalytic Converters - why do they go bad?
#1
Stock Catalytic Converters - why do they go bad?
I have ‘17 F-type R with only 20K miles now. One fine morning I had a check engine light on. The next day it went off and never came back on. I had it read and it showed multiple oxygen sensors and catalytic converter needing attention. Took it to dealer and they said it’s catalytic converter and not the o2 sensors. Surprisingly, I didn’t have any power issues, mpg variance, black smoke or bad smell for a week that I drove since the CEL had come on and went off. I am assuming it’s lightly clogged vs cooked out. Is this a common issue? I am wondering what could cause the catalytic converter to go bad? Are they bad design or is there some other underlying cause that needs to be addressed?
#2
I have ‘17 F-type R with only 20K miles now. One fine morning I had a check engine light on. The next day it went off and never came back on. I had it read and it showed multiple oxygen sensors and catalytic converter needing attention. Took it to dealer and they said it’s catalytic converter and not the o2 sensors. Surprisingly, I didn’t have any power issues, mpg variance, black smoke or bad smell for a week that I drove since the CEL had come on and went off. I am assuming it’s lightly clogged vs cooked out. Is this a common issue? I am wondering what could cause the catalytic converter to go bad? Are they bad design or is there some other underlying cause that needs to be addressed?
Put simply, the ECU (PCM - Powertrain Control Module - in JLR speak) is programmed to inject some fuel on the over-run which is then ignited in the exhaust system (purely by the heat). Dunno exactly where in the exhaust system this ignition takes place, could be before or after the cats (I'm guessing before) but either way is bad for the cats. Not just the explosions (viz the pops and bangs) but also and maybe more so unburned fuel going through the cats.
#3
#5
#6
Got my car back today. Only cats were replaced, o2’s were good. No software update (thank god!). Felt the car was breathing a little better and was a tad bit more responsive, but that could be a function of cooler weather too. It could be my cats were slightly clogged and hence the CEL was off. Anyhow, happy it was resolved quickly :-)
#7
Trending Topics
#8
This is the first time I've heard of Cataclean. What do we know about whether it works, any risks, experience with the AJ126 motor, etc. I currently use BG44K every 10K or so (annual for me). Can someone with pro level knowledge speak to the best treatment regimen. Switch to Cataclean? Use both every 10k, in separate tanks of gas of course? Alternate between C and BG?
https://www.holley.com/products/cataclean/
On a side note, I've read that detergent based cleaners like BG do a better job in general than solvent based ones lite Cataclean. Your thoughts?
https://www.holley.com/products/cataclean/
On a side note, I've read that detergent based cleaners like BG do a better job in general than solvent based ones lite Cataclean. Your thoughts?
The following users liked this post:
Supersprint Sport Exhausts (10-14-2023)
#9
I am not a pro either?
I can't say which is better but they are advertised for different purposes?
I use the BG44K but they make no claims that it cleans the catalytic converters?
I have never used Cataclean but that is their main claim it does clean catalytic converters.
Does it work? Don't know but have read several posts where a car failed emission testing and after using Cataclean the car passed.
Plus it's cheap and easy to do before replacing an expensive catalytic converter! So I don't see any downside even if it does not work.
But I don't think you can't compare them directly?
.
.
.
I can't say which is better but they are advertised for different purposes?
I use the BG44K but they make no claims that it cleans the catalytic converters?
I have never used Cataclean but that is their main claim it does clean catalytic converters.
Does it work? Don't know but have read several posts where a car failed emission testing and after using Cataclean the car passed.
Plus it's cheap and easy to do before replacing an expensive catalytic converter! So I don't see any downside even if it does not work.
But I don't think you can't compare them directly?
.
.
.
#10
Thet call Cataclean a fuel and exhaust system cleaner. "Restores, maintains & helps protect the catalytic converter, oxygen sensors, fuel injectors, cylinder heads and DPF (diesel particulate filter."
Sounds to me like they are billing it as equivalent to BG44K with an added benefit for the cat. Who has the real scoop?
Sounds to me like they are billing it as equivalent to BG44K with an added benefit for the cat. Who has the real scoop?
#11
Thet call Cataclean a fuel and exhaust system cleaner. "Restores, maintains & helps protect the catalytic converter, oxygen sensors, fuel injectors, cylinder heads and DPF (diesel particulate filter."
Sounds to me like they are billing it as equivalent to BG44K with an added benefit for the cat. Who has the real scoop?
Sounds to me like they are billing it as equivalent to BG44K with an added benefit for the cat. Who has the real scoop?
Last edited by RGPV6S; 10-16-2023 at 12:20 PM.
#12
I am unable to comprehend how those solvents would clean a cat.
I thought the problem with cat failure was primarily due to carbonation.
Those high volatiles solvents would just flush straight through with the exhaust and non would work on carbon build-up.
You might get a few nice exhaust flames!!
I thought the problem with cat failure was primarily due to carbonation.
Those high volatiles solvents would just flush straight through with the exhaust and non would work on carbon build-up.
You might get a few nice exhaust flames!!
#13
#14
With your CEL on, do you smell or see black smoke coming out of your exhaust? Has your mpg gone down? Does your drive feel sluggish at low and high RPM? If none of those, you could try cleaning it. Try the cataclean and see if that does the magic. If not, you are better off replacing it.
#15
#17
#20