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Misfire codes warning of catalytic converter

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

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YOUR RESEARCHMisfire codes warning of catalytic converter

Leading reported evidence

Disconnect battery

Performed · outcome unconfirmed

No successful repair reported for this finding.

0
Reported fixes: 0
Unsuccessful attempts: 1
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Discussions that performed work without a confirmed outcome: 1

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Performed · outcome unconfirmed · Original poster
For immediate results, I disconnected the battery.
Original post Read captured discussion
Misfire codes warning of catalytic converter

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

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Replace now

Performed · outcome unconfirmed

No successful repair reported for this finding.

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Reported fixes: 0
Unsuccessful attempts: 1
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Discussions that performed work without a confirmed outcome: 1

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Performed · outcome unconfirmed
Since you had the spark plugs replaced, now replace all your coil packs.
Original post Read captured discussion
Misfire codes warning of catalytic converter

Replace ignition coils

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Discussions that contain suggestions: 1

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Suggestion
Since you had the spark plugs replaced, now replace all your coil packs.
Original post Read captured discussion
Misfire codes warning of catalytic converter

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.

Disconnect battery

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 · Original poster
For immediate results, I disconnected the battery.
Original post Read captured discussion
Misfire codes warning of catalytic converter

Replace ignition coils

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
Since you had the spark plugs replaced, now replace all your coil packs.
Original post Read captured discussion
Misfire codes warning of catalytic converter

Replace now

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
Since you had the spark plugs replaced, now replace all your coil packs.
Original post Read captured discussion
Misfire codes warning of catalytic converter

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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.

3 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: 20261026T165820Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources

POST 1 / ORIGINAL POSTEROriginal post

Just hoping someone has experience with similar issues; my car is a 2002 996 C2, well cared for 72,000 miles. Service at 50K included new spark plugs, alll previous service done at dealer. I warned up the car a bit las week, and it threw a ck engine light, with misfire codes 300, 301, and 305. I may have the digits off, but all talk about catalytic converter. So, the question becomes what's going on? Car runs perfect, light is still on. Any insight appreciated. I'm not sure if previous owner did the coils or not. I have limited info from the dealer, as they won't give me the previous owner's records. Not too nice about it actually. Lots of records there, but will not release them to me.

POST 2Original post

Those are cylinder misfire codes. P0300 is general code for misfires. P0301 is cylinder one. P0305 is cylinder 5. Since you had the spark plugs replaced, now replace all your coil packs. You will need Durametric or OBDII reader with specific Porsche software (Foxwell N530) to clear your CEL. Then drive your car and see if any codes pop back up.

POST 3 / ORIGINAL POSTEROriginal post

Thanks for the response, and I hadn't had a code come up since owning the car several years now. For immediate results, I disconnected the battery. for a few minutes, the code cleared, I had to put the code in the radio, and I've driven three times with no recurring codes so far. I'm sure it will come back., and likely will end up getting the coils done. Everything I read indicated the coil packs as well as your advice here. When it comes back I'll have it done. Meanwhile I'll be shopping for a good indy mech to do it. Thanks, Gary

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