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P1128 Code - 986 Forum - The Community for Porsche Boxster & Cayman Owners

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

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YOUR RESEARCHP1128 Code - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Leading reported evidence

Check before

Suggestion or failed attempt

No successful repair reported for this finding.

0
Reported fixes
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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

Another thing to check before changing parts.

Original post Read captured discussion
P1128 Code - 986 Forum - The Community for Porsche Boxster & Cayman Owners
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Leading evidence: 'Check before' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Check before' (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 3 other evidence results

Clean mass air flow sensor

Suggestion or failed attempt

No successful repair reported for this finding.

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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

I tried cleaning the MAF to no avail.

Original post Read captured discussion
P1128 Code - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Run engine.html

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

http://986forum.com/forums/boxster-general-discussions/72288-p1128-p1130-running-fine-turned-into-barely-running-engine.html

Original post Read captured discussion
P1128 Code - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Smoke-test engine

Suggestion or failed attempt

No successful repair reported for this finding.

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Reported fixes
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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

If your Autel can read real time fuel trims you often see if you have vacuum leak without having to smoke test the engine.

Original post Read captured discussion
P1128 Code - 986 Forum - The Community for Porsche Boxster & Cayman Owners
Frequently discussed actions (4)

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

Check before

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

Another thing to check before changing parts.

Original post Read captured discussion
P1128 Code - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Clean mass air flow 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 · Original poster

I tried cleaning the MAF to no avail.

Original post Read captured discussion
P1128 Code - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Run engine.html

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

http://986forum.com/forums/boxster-general-discussions/72288-p1128-p1130-running-fine-turned-into-barely-running-engine.html

Original post Read captured discussion
P1128 Code - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Smoke-test engine

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

If your Autel can read real time fuel trims you often see if you have vacuum leak without having to smoke test the engine.

Original post Read captured discussion
P1128 Code - 986 Forum - The Community for Porsche Boxster & Cayman Owners
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.

  • 986Forum: 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: 20261027T161234Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources

POST 1 / ORIGINAL POSTEROriginal post

Howdy folks. I have been getting a recurring P1128 CEL code of late. I had it happen a while ago then it went away but now I am getting it every time I drive the car. No other codes such as P1130 have appeared. I have been just clearing them with my Autel. I tried cleaning the MAF to no avail. Am I looking at a replacement MAF or vacuum leak or O2 sensor? Any suggestions would be appreciated. Dave 2001S

POST 3Original post

I went thru the P1128 & P1130 issue last year. http://986forum.com/forums/boxster-general-discussions/72288-p1128-p1130-running-fine-turned-into-barely-running-engine.html A new MAF solved my problems. It seems like for many people on the forum a new MAF solves their problems. It is an easy to change part, but not the cheapest. With your code only being on one cylinder bank it may or may not be the culprit. If your Autel can read real time fuel trims you often see if you have vacuum leak without having to smoke test the engine. Search online for how to interpret long term and short term fuel trims. Can your Autel read O2 sensor voltage? Another thing to check before changing parts. I learned the hard way that having real time data helps so much to make an informed decision.

POST 4 / ORIGINAL POSTEROriginal post

Rex I was thinking vacuum leak but would I throw both codes or is it reasonable that a vacuum leak would only throw 1128 and not 1130?

POST 5Original post

I am not sure. It was a couple of years ago and I don't remember details. I was running out of time for CA reg/smog and just let the indy sort it out. I think they hooked it up to a smoke machine and just plugged whatever it was back in. They charged me for an hour and nothing for parts.

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