P0430 Code
Thread Starter
On The Tree
Joined: Jun 2014
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From: Saint Paul, MN
P0430 Code My SES light came on, saw that the code was P0430, which is supposedly for the cat, which I called Chevy and they said that the recall on those only lasted for 10yrs or 100k miles, which 2012 would have been the last year they would have replaced it for free. Am I losing any power or is anything going to be affected by not replacing the cat now?
Thanks!
Thanks!
Joined: Nov 2001
Posts: 34,647
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From: Schiller Park, ILL Member: #317
There is some misconception about what this code actually means. Some people think it automatically means that the cat is clogged (meaning power/MPG loss), and while it's certainly possible to get this code if a cat has become damaged enough to be clogged, there is no guaranty that you actually have a clog simply because of this code. In fact, there is no code at all that specifically indicates a clog or reduced flow.
P0430/P0420 simply indicates that the cat is below efficiency threshold, thus meaning that the oxygen storage capacity of the cat has been reduced to a point where emissions levels have increased beyond a preset level (determined by the PCM via a comparison between front and rear O2 readings for a given bank during a given test period). For example, if you were to remove/gut the cat, and not install O2 sims or custom tuning, you would receive this same code. It's not an indicator of flow, but rather ability to "scrub" the exhaust.
What seems to be a typical problem for the '00+ cats (and hence the factory warranty extension) is that the coatings on the substrate tend to wear off, and then emissions levels increase (causing this code). Sometimes cats do become clogged, but this is usually due to overheating (and thus melting) of the substrate (due to poor A/F mixture, and/or misfires, and/or afterfires in the exhaust system), and/or physical damage to the cat body that breaks apart the substrate and causes it to become lodged in a way that blocks flow.
P0430/P0420 simply indicates that the cat is below efficiency threshold, thus meaning that the oxygen storage capacity of the cat has been reduced to a point where emissions levels have increased beyond a preset level (determined by the PCM via a comparison between front and rear O2 readings for a given bank during a given test period). For example, if you were to remove/gut the cat, and not install O2 sims or custom tuning, you would receive this same code. It's not an indicator of flow, but rather ability to "scrub" the exhaust.
What seems to be a typical problem for the '00+ cats (and hence the factory warranty extension) is that the coatings on the substrate tend to wear off, and then emissions levels increase (causing this code). Sometimes cats do become clogged, but this is usually due to overheating (and thus melting) of the substrate (due to poor A/F mixture, and/or misfires, and/or afterfires in the exhaust system), and/or physical damage to the cat body that breaks apart the substrate and causes it to become lodged in a way that blocks flow.
Thread Starter
On The Tree
Joined: Jun 2014
Posts: 178
Likes: 0
From: Saint Paul, MN
There is some misconception about what this code actually means. Some people think it automatically means that the cat is clogged (meaning power/MPG loss), and while it's certainly possible to get this code if a cat has become damaged enough to be clogged, there is no guaranty that you actually have a clog simply because of this code. In fact, there is no code at all that specifically indicates a clog or reduced flow.
P0430/P0420 simply indicates that the cat is below efficiency threshold, thus meaning that the oxygen storage capacity of the cat has been reduced to a point where emissions levels have increased beyond a preset level (determined by the PCM via a comparison between front and rear O2 readings for a given bank during a given test period). For example, if you were to remove/gut the cat, and not install O2 sims or custom tuning, you would receive this same code. It's not an indicator of flow, but rather ability to "scrub" the exhaust.
What seems to be a typical problem for the '00+ cats (and hence the factory warranty extension) is that the coatings on the substrate tend to wear off, and then emissions levels increase (causing this code). Sometimes cats do become clogged, but this is usually due to overheating (and thus melting) of the substrate (due to poor A/F mixture, and/or misfires, and/or afterfires in the exhaust system), and/or physical damage to the cat body that breaks apart the substrate and causes it to become lodged in a way that blocks flow.
P0430/P0420 simply indicates that the cat is below efficiency threshold, thus meaning that the oxygen storage capacity of the cat has been reduced to a point where emissions levels have increased beyond a preset level (determined by the PCM via a comparison between front and rear O2 readings for a given bank during a given test period). For example, if you were to remove/gut the cat, and not install O2 sims or custom tuning, you would receive this same code. It's not an indicator of flow, but rather ability to "scrub" the exhaust.
What seems to be a typical problem for the '00+ cats (and hence the factory warranty extension) is that the coatings on the substrate tend to wear off, and then emissions levels increase (causing this code). Sometimes cats do become clogged, but this is usually due to overheating (and thus melting) of the substrate (due to poor A/F mixture, and/or misfires, and/or afterfires in the exhaust system), and/or physical damage to the cat body that breaks apart the substrate and causes it to become lodged in a way that blocks flow.
Joined: Nov 2001
Posts: 34,647
Likes: 2,573
From: Schiller Park, ILL Member: #317
Thanks for the reply, you always hit me with a ton of knowledge - much appreciated. I only have 48K on the vehicle, so it shouldn't be too worn out or anything, but maybe? I suppose it's going to snow soon, so I'll just store it for the winter and get a whole new exhaust come spring time. As far as the flow and how powerful it feels, it feels the same and just as good as it always has.. I'm not noticing any loss of power or anything funny happening, just a stupid SES light that I hate looking at.
Some of the factory '00+ cats had this problem even at low mileages (coatings wearing off substrate). As you mentioned, GM extended the warranty for this condition, but at this point it's expired for all of them.
FWIW, my '02 car developed this code back in the fall of '11. It had an early in-service date of 10/01, so the warranty extension had expired by about a month when the code popped up. I just disabled the code and didn't give it another thought. The car was a stock daily driver and I put many thousands more miles on it over the 2+ more years that I owned it. There was never any difference in power or MPG at any point.
The code is only a problem if you need to pass an OBD scan emissions test (or a sniffer test, as the cat is no longer properly scrubbing the exhaust). Custom tuning/O2 sims can take care of the code though. If you're planning a whole new exhaust in the near future, you can simply ignore the code for now though.
Thread Starter
On The Tree
Joined: Jun 2014
Posts: 178
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From: Saint Paul, MN
I'm always glad to share knowledge and help others who are interested in the info.
Some of the factory '00+ cats had this problem even at low mileages (coatings wearing off substrate). As you mentioned, GM extended the warranty for this condition, but at this point it's expired for all of them.
FWIW, my '02 car developed this code back in the fall of '11. It had an early in-service date of 10/01, so the warranty extension had expired by about a month when the code popped up. I just disabled the code and didn't give it another thought. The car was a stock daily driver and I put many thousands more miles on it over the 2+ more years that I owned it. There was never any difference in power or MPG at any point.
The code is only a problem if you need to pass an OBD scan emissions test (or a sniffer test, as the cat is no longer properly scrubbing the exhaust). Custom tuning/O2 sims can take care of the code though. If you're planning a whole new exhaust in the near future, you can simply ignore the code for now though.
Some of the factory '00+ cats had this problem even at low mileages (coatings wearing off substrate). As you mentioned, GM extended the warranty for this condition, but at this point it's expired for all of them.
FWIW, my '02 car developed this code back in the fall of '11. It had an early in-service date of 10/01, so the warranty extension had expired by about a month when the code popped up. I just disabled the code and didn't give it another thought. The car was a stock daily driver and I put many thousands more miles on it over the 2+ more years that I owned it. There was never any difference in power or MPG at any point.
The code is only a problem if you need to pass an OBD scan emissions test (or a sniffer test, as the cat is no longer properly scrubbing the exhaust). Custom tuning/O2 sims can take care of the code though. If you're planning a whole new exhaust in the near future, you can simply ignore the code for now though.
Thanks, again. I assumed it wouldn't be too much of a problem, but just wanted to double check on the forums. I guess I will need to break out the electricians tape and cover up the SES light!
TECH Apprentice
Joined: Feb 2003
Posts: 352
Likes: 1
From: Macedon,NY
I had that same code last year when i put in Gumout 4 in 1 fuel system cleaner, I guess it cleaned it too good and some gunk got on the o2 sensor, it went away 2 weeks later never to come back and even passed the NYS emissions test.
