Rennlist

Next Step? P0430 Code

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Original source

2 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis

THIS DISCUSSION / SOURCE-DERIVED OVERVIEW

Discussion summary

YOUR RESEARCHNext Step? P0430 Code

Leading reported evidence

Replace cats or some other option

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 · Original poster
Reading through another P0430 thread it seems that I am at the stage of replacing the cats or some other option.
Original post Read captured discussion
Next Step? P0430 Code

Read full discussion summary

Leading evidence: 'Replace cats or some other option' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Replace cats or some other option' (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.

Read captured replies

1 matching discussions · 2 captured posts examined · 0 partial discussions

Compare 2 other evidence results

Use fresh gas (as it was sitting

Suggestion or failed attempt

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 · Original poster
I have a local German auto shop that I have always trusted and we did simple things first to use fresh gas (as it was sitting for awhile).
Original post Read captured discussion
Next Step? P0430 Code

Use these mini cats, and no codes so far

Suggestion or failed attempt

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
Now using these mini cats, and no codes so far:
Original post Read captured discussion
Next Step? P0430 Code

Frequently discussed actions (3)

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

Replace cats or some other option

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 · Original poster
Reading through another P0430 thread it seems that I am at the stage of replacing the cats or some other option.
Original post Read captured discussion
Next Step? P0430 Code

Use fresh gas (as it was sitting

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 · Original poster
I have a local German auto shop that I have always trusted and we did simple things first to use fresh gas (as it was sitting for awhile).
Original post Read captured discussion
Next Step? P0430 Code

Use these mini cats, and no codes so far

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
Now using these mini cats, and no codes so far:
Original post Read captured discussion
Next Step? P0430 Code

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.

2 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.

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

Outcome without a verified action link
CEL came back.
Original post Read captured discussion
No unique explicit quoted action; no causal link assigned

Generation: 20261026T055238Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources

POST 1 / ORIGINAL POSTEROriginal post

I drive a 2003 996 Cabriolet with 100K+ miles on it and my CEL recently showed P0430 Catalyst System Efficiency Below Threshold Bank 2. I have a local German auto shop that I have always trusted and we did simple things first to use fresh gas (as it was sitting for awhile). CEL came back. We then change plugs / coils (needed them anyways) and CEL came back. Most recently did the O2 sensors (4) and initially they said the readings on their monitors looked better and were hopeful of a fix. I felt the car did drive better as well but sure enough after about 70 miles of driving the CEL came back, same code. The shop adequately forewarned that these may not be the cure and if this failed it was going to be the cats. Reading through another P0430 thread it seems that I am at the stage of replacing the cats or some other option. Obviously a 996 Cab, Tip with 100k+ miles does not have tremendous value left but still is an enjoyable drive - just wondering some thoughts from the group or similar experiences. I know OEM Cats are very expensive and considering the car, this would not likely make much sense. I have been looking at the Fabspeed options (eg. Sport Cat-X pipe). I know Cargraphic has a similar one as well. Both state that the Cats will correct the CEL and pass emissions (I'm in PA) but I know I have read other sources not to trust any Cats except OEM. I like the idea of improving the sound of the car but certainly am not looking for anything obnoxiously loud. Anyone with similar experience with their 996 and what did you do or recommend? Much thanks.

POST 2Original post

I was getting P0420 and P0430 after switching to cats from Top Gear UK. First tried stacking some spark plug non-foulers, but codes came back. Now using these mini cats, and no codes so far: https://www.racdyn-usa.com/PROD/130+10+10+014.html

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