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P0422 code when dropping 1500-2000ft in elevation - 986 Forum - The Community for Porsche Boxster & Cayman Owners

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YOUR RESEARCHP0422 code when dropping 1500-2000ft in elevation - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Leading reported evidence

Check engine codes occasionally

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
My 2001 S has started throwing check engine codes occasionally when the elevation drops my 1500-2000 ft (I live in the mountains).
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P0422 code when dropping 1500-2000ft in elevation - 986 Forum - The Community for Porsche Boxster & Cayman Owners

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Leading evidence: 'Check engine codes occasionally' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Check engine codes occasionally' (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 · 1 captured posts examined · 0 partial discussions

Compare 3 other evidence results

Check just as there is a 5%

Suggestion or failed attempt

No successful repair reported for this finding.

0
Reported fixes: 0
Unsuccessful attempts: 1
Discussions

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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
The question therefore is this real or as a result of the car deciding to run the evap check just as there is a 5% change in atmospheric pressure.
Original post Read captured discussion
P0422 code when dropping 1500-2000ft in elevation - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Check works, a rapid

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
From what I can understand of the way the vacuum check works, a rapid change in ambient pressure would be exactly the thing the computer would see as a minor fault.
Original post Read captured discussion
P0422 code when dropping 1500-2000ft in elevation - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Run evap

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
The question therefore is this real or as a result of the car deciding to run the evap check just as there is a 5% change in atmospheric pressure.
Original post Read captured discussion
P0422 code when dropping 1500-2000ft in elevation - 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 engine codes occasionally

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
My 2001 S has started throwing check engine codes occasionally when the elevation drops my 1500-2000 ft (I live in the mountains).
Original post Read captured discussion
P0422 code when dropping 1500-2000ft in elevation - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Check just as there is a 5%

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
The question therefore is this real or as a result of the car deciding to run the evap check just as there is a 5% change in atmospheric pressure.
Original post Read captured discussion
P0422 code when dropping 1500-2000ft in elevation - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Check works, a rapid

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
From what I can understand of the way the vacuum check works, a rapid change in ambient pressure would be exactly the thing the computer would see as a minor fault.
Original post Read captured discussion
P0422 code when dropping 1500-2000ft in elevation - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Run evap

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
The question therefore is this real or as a result of the car deciding to run the evap check just as there is a 5% change in atmospheric pressure.
Original post Read captured discussion
P0422 code when dropping 1500-2000ft in elevation - 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.

1 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: 20261026T120458Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources

POST 1 / ORIGINAL POSTEROriginal post

My 2001 S has started throwing check engine codes occasionally when the elevation drops my 1500-2000 ft (I live in the mountains). Specifically the P0442 Porsche code 97 minor leak in evaporation system. The question therefore is this real or as a result of the car deciding to run the evap check just as there is a 5% change in atmospheric pressure. Significantly, this happened today right around a drop and the fuel level dropping below 3/4. I believe that can trigger the evap check to occur. From what I can understand of the way the vacuum check works, a rapid change in ambient pressure would be exactly the thing the computer would see as a minor fault. The forum search is not working for me (ticket has expired), but searching around, the usual culprits in order of frequency to throw this fault are, gas cap, vent valve, purge valve. However diagnosing the system is stated to be tricky even for a pro with the correct gear. Thoughts? Will the fault clear after three engine start cycles or will I have to clear it with the reader each time? Should I start with the R&R the parts in order, or is this one for the pros? Alternatively, did the engineers just not think through this driving scenario and are all 986s prone to this when in the mountains? Many thanks Philip

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