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Aging of HO2S on scanner

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

Discussion summary

YOUR RESEARCHAging of HO2S on scanner

Leading reported evidence

Replace on heat or oil pressure, no longer any smoke

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
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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

Smoke came from engine compartment, no sign of overheating, no odd engine noise, more like a spritz from some where on engine and after spending some time looking and listening did a restart, no changes on heat or oil pressure, no longer any smoke.

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Aging of HO2S on scanner
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Leading evidence: 'Replace on heat or oil pressure, no longer any smoke' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Replace on heat or oil pressure, no longer any smoke' (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 · 8 captured posts examined · 0 partial discussions

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Replace upstream o2 sensor

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

Change the upstream O2 sensor.

Original post Read captured discussion
Aging of HO2S on scanner
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 on heat or oil pressure, no longer any smoke

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

Smoke came from engine compartment, no sign of overheating, no odd engine noise, more like a spritz from some where on engine and after spending some time looking and listening did a restart, no changes on heat or oil pressure, no longer any smoke.

Original post Read captured discussion
Aging of HO2S on scanner

Replace upstream o2 sensor

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

Change the upstream O2 sensor.

Original post Read captured discussion
Aging of HO2S on scanner
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.

8 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: 20261026T091943Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources

POST 1 / ORIGINAL POSTEROriginal post

The full screen reads P1275 in red, the Aging Of HO2S Ahead of TWC Cyl. 1-3. Need some help with the translation, please. 2000 996 C2 cab 134,000 miles, driven well, seldom under 3000 rpm, mountain roads 4k-6k ALSO was driving well on a recent mountain trip when I noticed smoke coming out of the rear, no signs of overheating or oil pressure drop, popped cover, smoke from right side, no acrid smell, smoke seemed grayish. Let it cool then drove carefully at low rpm's home, 40 miles, stopped at shop for quick look but could not see or hear a leak.car in garage for 48hrs with cardboard underneath and no drips, oil level spot on. anyone with similar experience or thoughts, again please

POST 2Original post

🔧 Plain English • HO2S = Heated Oxygen Sensor • Ahead of TWC = Before the catalytic converter (upstream) • Cyl. 1–3 = Bank 1 on a 996 engine • Aging = The sensor is slow to respond, drifting out of spec Your friend’s 2000 Porsche 911 is telling him the upstream O2 sensor on Bank 1 is worn out this is what AI says

POST 3Original post

Quotes source post: 20481550

Steve, the exhaust smoke may be from a failing AOS. Check out the recently posted threads on the AOS and UAOS.

POST 5 / ORIGINAL POSTEROriginal post

Smoke came from engine compartment, no sign of overheating, no odd engine noise, more like a spritz from some where on engine and after spending some time looking and listening did a restart, no changes on heat or oil pressure, no longer any smoke. Had scheduled service time for the O2 sensor at end of month and they will inspect. A garage model until then.

POST 6Original post

Quotes source post: 20482746

AOS will be exhaust smoke. Would love to hear what caused it after your service inspection.

POST 7 / ORIGINAL POSTEROriginal post

I appreciated the redirect and do have AAA as well as Hagerty but did not recognize imminent danger. Had the smoke been constant or engine sounded off it would have gone to the flat bed, for sure. It was a gorgeous top-down drive in spring like weather.

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