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Discussion Starter · #1 · (Edited)
Ok, I want to start by acknowledging that there are already tons of posts about the P0430 code, I know that. As I’ve spent probably 12 hours scouring over them this week since my light came on, but I feel pretty much in the same place I started when it comes to solving the issue. If not more confused, could it be something besides my cat?

I feel like I don’t have the common issues that most notice with a p0430, I actually got the best mileage I’d ever had during the two days before the light came on, no rotten egg smell, no smoke, nothing like that. I put a bottle of cataclean in it and drove 100 miles straight after but the light has stayed on, so maybe I just need to drive it around some more.

I’ve attached some pictures with info I got from a neighbors code reader, but to be honest with you I don’t understand it as I just don’t know much yet. Maybe this would help me diagnose if it’s really the cat or not?

I’m curious as to how I should proceed, do I
-Clear the code and see if it comes back on?
-Leave the light on and see if it goes off after more driving?
-Bite the bullet and just take it in?

I’ve seen in rare cases not doing anything could really mess up my engine if some of the material gets sucked in there. Is that a legitimate concern or something I don’t actually need to worry about?

Also, 2006 with 217,000 miles. I’ve had it for about the last 20,000

I’m hoping to get out on some multi week trips this summer and want to get this taken care of before I do so.

Thank you for any help you can give me!
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This code usually means your cat is not working at full efficiency and needs to be replaced.

The front O2 sensors are in the manifolds in front of the primary cats & actually help the engine computer control fuel trims & timing.

Your rear O2 sensors are behind the primary cats & only there to compare the reading from the front O2 sensors & trigger a code (P0420 & P0430 depending on bank) if the difference is outside acceptable parameters.

While it is possible the sensors aren't working optimally, since they are not triggering a code it is far more probable your cat is not operating at full efficiency.

Lots of things can cause this. If you want to save money pull the cat and inspect. As long as the material is intact, has its (honeycomb) structure, and isn't severely discolored or fouled, it is safe to drive (if these issues are present, change it immediately to avoid potential catastrophic engine issues).

At that point reset the code and I would suggest a tune-up to fix any potential root causes. It may come back soon, every few months, or not at all.

OP, you didn't say year, mileage, maintenance history, or any other problems you have had with the vehicle?

Provide that and people can give better advice.
 

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If your sensors are bad you will get either a rich or lean code, or a sensor out of range code. I think they are for example P0171, or P2A03.

P0430 is almost always a cat - as simpleX indicated. The actual error description is "cat efficiency low" or something like that.

Having said that - it appears your running just slightly rich. LTFT are negative, meaning its pulling fuel out of the loop (ie running rich prior to the LTFT adjustment). There not that bad - you won't get a rich code until -20%, ideally you would want them around +/- 5% or less. However if your cats are starting to get a bit plugged it could be backing things up - making it run rich.

If your P0430 is not your CAT then you will be the first one I have ever seen here that it isn't and I have been here a while. However if you want to be sure - others here have indicated running some cataclean gets rid of the code for a time. If you do some cataclean and it goes away a while then comes back - its almost certainly the cat. Do note however that a few people have destroyed their engine running their cats with that code. If they implode while your driving your almost sure to suck debris into the engine and ruin it - and its happened here a few times.
 

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Discussion Starter · #4 ·
This code usually means your cat is not working at full efficiency and needs to be replaced.

The front O2 sensors are in the manifolds in front of the primary cats & actually help the engine computer control fuel trims & timing.

Your rear O2 sensors are behind the primary cats & only there to compare the reading from the front O2 sensors & trigger a code (P0420 & P0430 depending on bank) if the difference is outside acceptable parameters.

While it is possible the sensors aren't working optimally, since they are not triggering a code it is far more probable your cat is not operating at full efficiency.

Lots of things can cause this. If you want to save money pull the cat and inspect. As long as the material is intact, has its (honeycomb) structure, and isn't severely discolored or fouled, it is safe to drive (if these issues are present, change it immediately to avoid potential catastrophic engine issues).

At that point reset the code and I would suggest a tune-up to fix any potential root causes. It may come back soon, every few months, or not at all.

OP, you didn't say year, mileage, maintenance history, or any other problems you have had with the vehicle?

Provide that and people can give better advice.
I do think it’s probably just my cat, as you say. I’d like to remove and check them out, maybe clean but unfortunately I’m not that savvy. I’m hoping to get my friend who is to help me out though and save some money if I can. Thanks for letting me know what to check out if I can take them off. And I’ll add that info into my original post as well, first post so still figuring it out!
 

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Discussion Starter · #5 ·
If your sensors are bad you will get either a rich or lean code, or a sensor out of range code. I think they are for example P0171, or P2A03.

P0430 is almost always a cat - as simpleX indicated. The actual error description is "cat efficiency low" or something like that.

Having said that - it appears your running just slightly rich. LTFT are negative, meaning its pulling fuel out of the loop (ie running rich prior to the LTFT adjustment). There not that bad - you won't get a rich code until -20%, ideally you would want them around +/- 5% or less. However if your cats are starting to get a bit plugged it could be backing things up - making it run rich.

If your P0430 is not your CAT then you will be the first one I have ever seen here that it isn't and I have been here a while. However if you want to be sure - others here have indicated running some cataclean gets rid of the code for a time. If you do some cataclean and it goes away a while then comes back - its almost certainly the cat. Do note however that a few people have destroyed their engine running their cats with that code. If they implode while your driving your almost sure to suck debris into the engine and ruin it - and its happened here a few times.
Thank you for helping explain the pictures of the reader, and I am coming to the conclusion it’s almost certainly my cat. Tried the cataclean but my light is still on, not sure if it just needs more time or if it just didn’t work for me. Either way I’m definitely not trying to destroy my engine! That’s being said I’m thinking I might just clear it and see if it comes on again.
 

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I do think it’s probably just my cat, as you say. I’d like to remove and check them out, maybe clean but unfortunately I’m not that savvy. I’m hoping to get my friend who is to help me out though and save some money if I can. Thanks for letting me know what to check out if I can take them off. And I’ll add that info into my original post as well, first post so still figuring it out!

They can't be cleaned in a meaningful way but the primaries are pretty easy to access to visually inspect. If you disconnect the secondary pipes you'll get a clear view of the internals of the primaries. That said, it's almost certainly a bad cat with that mileage. You can try replacing sensors but it's almost always the cat itself that needs replacing.
 
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