17 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCHFailed emissions
Leading reported evidence
Replace along
Performed · outcome unconfirmed
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 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
I have a low T in my 996 replaced along with WP a few months ago.
Leading evidence: 'Replace along' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Adjust coolant temp' (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.
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
The factory DME tune has more than enough flexibility to adjust for the coolant temp change.
Check cam deviation values or engine sump vacuum levels
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
Good examples of why this is important are the misleading results you get when you check cam deviation values or engine sump vacuum levels on a car that is not steady state.
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 it sat for "a few months", particularly without fuel stabilizer in it, I would dump Techron in the tank and take if for a hard run before checking its fuel trims.
Replace air filter, spark plugs, oil, and drive it aggressively
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 air filter, spark plugs, oil, and drive it aggressively for a few days then take it to test again.
Check cam deviation values or engine sump vacuum levels
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
Good examples of why this is important are the misleading results you get when you check cam deviation values or engine sump vacuum levels on a car that is not steady state.
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 it sat for "a few months", particularly without fuel stabilizer in it, I would dump Techron in the tank and take if for a hard run before checking its fuel trims.
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 it sat for "a few months", particularly without fuel stabilizer in it, I would dump Techron in the tank and take if for a hard run before checking its fuel trims.
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.
17 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.
Pelican Parts: 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: 20261026T172408Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources
2005 Porsche 996 c4s
46000 miles
Took car for mot today after being sat for 6 months and failed emissions.
Before i took her i filled it up with new fuel and gave it a few blasts up and down the road to get cats hot.Its only done 429 miles since last mot which it passed emissions ok.
High CO levels normally result from over rich air fuel ratios, which could be anything from a dirty air filter to a sensor issue. If you have access to a Porsche specific scan tool like the Durametric system, check you fuel trims for over fueling.
That is the problem. The lower temperature thermostat is telling the CPU to enrich the mixture in order to warm the engine up some more. Since it can never do that with the new lower thermostat, it will not pass … smog.
Options are to …
1. Reprogram the CPU, Hard
2. Replace with stock thermostat to bring the engine operating temperature up, easier
3. Give the car a tune up while you are at it. Change the air filter, spark plugs, oil, and drive it aggressively for a few days then take it to test again.
Sorry, but that is utter nonsense. We have a couple hundred customers running 160F thermostats, and NONE of them have ANY issues. The factory DME tune has more than enough flexibility to adjust for the coolant temp change.
Then your experience is different from mine. I will believe it when you can dis-assemble the CPU code and show that the CPU is programmed to deal with 160F water temperature.
Let me make this simple, so that you can understand it: If the DME was unable to cope with the mixture conditions at 160F, your car would code every time it warmed up with the factory thermostat and reached 160f on its way to its 205-210F normal operating range. Obviously, that does not happen, or every Porsche owner would be coding every day..........
If it sat for "a few months", particularly without fuel stabilizer in it, I would dump Techron in the tank and take if for a hard run before checking its fuel trims.
The cats are heated by exhaust gases, which do not change much in temperature as a function of coolant temperatures, they are more a function of air/fuel ratios.
The reasons for getting the car up to "normal operating conditions", or steady state as it is known in the trade, is to allow everything to come to equilibrium. Good examples of why this is important are the misleading results you get when you check cam deviation values or engine sump vacuum levels on a car that is not steady state.
This is a source reference. Confirm exact model applicability in the original material.
