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Misfire and Smell of Sulphur

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

THIS DISCUSSION / SOURCE-DERIVED OVERVIEW

Discussion summary

YOUR RESEARCHMisfire and Smell of Sulphur

Leading reported evidence

Replace radiator cap at £10

Suggestion or failed attempt

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 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
Long time, no post (last post resulted in Richard H advice to replace radiator cap at £10 when OPC wanted to fit new radiators as an £800 'precaution'.)
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Misfire and Smell of Sulphur

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Leading evidence: 'Replace radiator cap at £10' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Replace radiator cap at £10' (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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1 matching discussions · 6 captured posts examined · 0 partial discussions

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Replace spark plugs

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
You have to take them off to change the spark plugs, so it is a regular service item.
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Misfire and Smell of Sulphur

Frequently discussed actions (2)

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

Replace radiator cap at £10

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
Long time, no post (last post resulted in Richard H advice to replace radiator cap at £10 when OPC wanted to fit new radiators as an £800 'precaution'.)
Original post Read captured discussion
Misfire and Smell of Sulphur

Replace spark plugs

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
You have to take them off to change the spark plugs, so it is a regular service item.
Original post Read captured discussion
Misfire and Smell of Sulphur

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.

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

Porsche Club GB: 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: 20261026T163944Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources

POST 1 / ORIGINAL POSTEROriginal post

Hi All Long time, no post (last post resulted in Richard H advice to replace radiator cap at £10 when OPC wanted to fit new radiators as an £800 'precaution'.) Have had occasional misfire of late, usually when cold but gone when warm which I put down to lay up over winter/lack of use. Misfire became permanent at the weekend, emissions light flashing and now on permanently and strongish smell of sulphur in the car after a few minutes of this. Was only a mile from home so got back on light throttle. Any thoughts? Will get to an indy on a trailer to have checked out but any thoughts appreciated. Thanks Hugh

POST 2Original post

I don't know too much about 996s but it sounds like a catalytic converter issue to me. They tend to break down over time and create clogging or back-pressure problems. I'm sure a kettle owner will be able to help in more detail.

POST 3Original post

Could be coil packs. A misfire/lack of spark could be putting unburnt fuel into the cats. Best get it checked out pronto.

POST 4 / ORIGINAL POSTEROriginal post

Thanks Richard, are coil packs an engine out replacement? Don't intend to run it at all until diagnosed/sorted, I was very close to home when it couldn't clear itself - will keep you posted.

POST 5Original post

I would also support Richards statement. Had my coils replaced as part of my service. I'm not aware that they took the engine out. Approx £35 per coil at an indie. Good luck

POST 6Original post

No, it can be done easily without. You have to take them off to change the spark plugs, so it is a regular service item. Unless it's a Turbo, in which case it's a marathon.

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