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replacing cats..

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5 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW

Discussion summary

YOUR RESEARCHreplacing cats..

Leading reported evidence

Replace both

Performed · outcome unconfirmed

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
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Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.

Discussions that performed work without a confirmed outcome
1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Performed · outcome unconfirmed

Both were replaced in the last 10K miles.

replacing cats..
Read full discussion summary

Leading evidence: 'Replace both' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Replace both' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.

Source reports, not a diagnosis or a success probability. Counts refer to discussions and can overlap.

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1 matching discussions · 5 captured posts examined · 0 partial discussions

Compare 4 other evidence results

Replace recently and the other need

Performed · outcome unconfirmed

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context

Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.

Discussions that performed work without a confirmed outcome
1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Performed · outcome unconfirmed

One of my ctas was replaced recently and the other need to be replace soon.

replacing cats..

Replace under cpo

Performed · outcome unconfirmed

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context

Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.

Discussions that performed work without a confirmed outcome
1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Performed · outcome unconfirmed

I've had both of mine replaced under CPO.

replacing cats..

Replace several o2 sensors and yet not one converter

Suggestion or failed attempt

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context

Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.

Discussions that contain suggestions
1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion

I've had to replace several O2 sensors and yet not one converter, but....

replacing cats..

Replace soon

Suggestion or failed attempt

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context

Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.

Discussions that contain suggestions
1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion

One of my ctas was replaced recently and the other need to be replace soon.

replacing cats..
Frequently discussed actions (7)

These are separate views of the same evidence. Frequency alone does not establish a fix, and these counts must not be added together.

Replace both

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Discussions that performed work without a confirmed outcome
1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Performed · outcome unconfirmed

Both were replaced in the last 10K miles.

replacing cats..

Replace recently and the other need

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Discussions that performed work without a confirmed outcome
1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Performed · outcome unconfirmed

One of my ctas was replaced recently and the other need to be replace soon.

replacing cats..

Replace several o2 sensors and yet not one converter

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Discussions that contain suggestions
1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion

I've had to replace several O2 sensors and yet not one converter, but....

replacing cats..

Replace soon

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Discussions that contain suggestions
1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion

One of my ctas was replaced recently and the other need to be replace soon.

replacing cats..

Replace under cpo

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Discussions that performed work without a confirmed outcome
1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Performed · outcome unconfirmed

I've had both of mine replaced under CPO.

replacing cats..

Use by the converter

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Discussions that contain suggestions
1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion

The signal from a #2 sensor that is after a properly functioning converter should signal an absence of oxygen with the assumption the oxygen was used by the converter.

replacing cats..

Use when the exhaust gas is low in oxygen content

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Discussions that contain suggestions
1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion

When the signal indicates oxygen is present above a certain level this is because the converter can't store the oxygen in times of excess oxygen in the exhaust gases for use when the exhaust gas is low in oxygen content.

replacing cats..
Coverage and how to read this overview

Counts describe captured discussions, not unique people or a diagnosis. Author identities are not reliably stored. Exact duplicate evidence is counted once across matching discussions; one discussion counts at most once per action/state. Multiple repairs reported together remain a combination. Suggestions and failed attempts do not establish a fix. Matches cover whole discussions and can include related faults, model variants and incomplete threads.

5 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.

  • Rennlist: 1 discussions

0 evidence records excluded for query context · 0 excluded by outcome qualification · 0 adjusted by outcome qualification.

0 acknowledgements have no verified action link; they do not establish a repair result.

Generation: 20261026T074343Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources

POST 1 / ORIGINAL POSTEROriginal post

how do cats go bad causing need for replacement? are the stock cats prone to this problem? do all cats have a "lifespan"?

POST 2Original post

Quotes source post: 6067357

I've had both of mine replaced under CPO. I don't know what came loose internally but it sounded like hell when it did. BTW, my car is an '03 with 61K miles. Both were replaced in the last 10K miles.

POST 3Original post

One of my ctas was replaced recently and the other need to be replace soon. 86,000km Porsche has a 8 year warranty on Cats.

POST 4Original post

Quotes source post: 6067357

they wear out. The active layer of catalytic metal is just atoms thick and while these atoms are pretty tightly bound to each other and their base metal they can break loose over time. As they do the efficiency of the converter to store oxygen for post processing of exhaust gases is diminished. When it decreases to a certain threshold the engine controller determines this by the signal being generated by the post-converter O2 sensor. It starts to generate a signal that it is in some way too much like the signal being generrated by the #1 or pre-converter O2 sensor. The signal from the #1 sensor varies because the engine controller constantly alternates between supplying the engine with a rich then lean mixture on the order of just a fraction of a percent richer or leaner than ideal (approx. 14.72:1). The signal from a #2 sensor that is after a properly functioning converter should signal an absence of oxygen with the assumption the oxygen was used by the converter. When the signal indicates oxygen is present above a certain level this is because the converter can't store the oxygen in times of excess oxygen in the exhaust gases for use when the exhaust gas is low in oxygen content. Are you sure converters are bad? How? A bad or going bad O2 sensor can fool you. I've had to replace several O2 sensors and yet not one converter, but.... ....I've got over 207,000 miles on my engine's converters and one still works just fine. The other one doesn't work so good. The engine controller generates a P0430 error code almost every day now. The converter is just worn out. Sincerely, Macster.

POST 5Original post

Macster: Thanks for the explanation. I have wondered just exactly this--I knew there were O2 sensors, but really did not know the mechanism. It sounds like I will get an error if my cats quit working.

This is a source reference. Confirm exact model applicability in the original material.