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THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCH996.2 3.6 P0302/P0300 Misfire Only Under High RPM/Load ? Looking for Advice
Leading reported evidence
Check spark plug and coil, and nothing obvious looked wrong
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
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0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Performed · outcome unconfirmed · Original poster
Checked the spark plug and coil, and nothing obvious looked wrong.
996.2 3.6 P0302/P0300 Misfire Only Under High RPM/Load ? Looking for Advice
Read full discussion summary
Leading evidence: 'Check spark plug and coil, and nothing obvious looked wrong' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Check next' (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 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 · Original poster
The engine had a new updated short block installed around 66k miles.
996.2 3.6 P0302/P0300 Misfire Only Under High RPM/Load ? Looking for Advice
Replace #2 fuel injector
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 · Original poster
Swapped the #2 fuel injector with #3 misfire still stayed on cylinder 2.
996.2 3.6 P0302/P0300 Misfire Only Under High RPM/Load ? Looking for Advice
Replace #2 ignition coil
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 · Original poster
Swapped the #2 ignition coil with #3 misfire stayed on cylinder 2.
996.2 3.6 P0302/P0300 Misfire Only Under High RPM/Load ? Looking for Advice
Replace #2 spark plug
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 · Original poster
Swapped the #2 spark plug with #3 misfire stayed on cylinder 2.
996.2 3.6 P0302/P0300 Misfire Only Under High RPM/Load ? Looking for Advice
Check valve springs
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
With what you have already ruled out and your symptoms of the code setting on higher RPM and Load, I would pull the valve cover and check the valve springs for breakage, and inspect the lifters for damage....and inspect the cam lobes
996.2 3.6 P0302/P0300 Misfire Only Under High RPM/Load ? Looking for Advice
Inspect cam lobes
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
With what you have already ruled out and your symptoms of the code setting on higher RPM and Load, I would pull the valve cover and check the valve springs for breakage, and inspect the lifters for damage....and inspect the cam lobes
996.2 3.6 P0302/P0300 Misfire Only Under High RPM/Load ? Looking for Advice
Inspect lifters
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
With what you have already ruled out and your symptoms of the code setting on higher RPM and Load, I would pull the valve cover and check the valve springs for breakage, and inspect the lifters for damage....and inspect the cam lobes
996.2 3.6 P0302/P0300 Misfire Only Under High RPM/Load ? Looking for Advice
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: 20261027T064914Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources
I�m chasing a misfire issue on my 2002 Porsche 996.2 Carrera 3.6L.
The car is throwing P0302 (Cylinder 2 Misfire) and sometimes P0300 (Random/Multiple Cylinder Misfire). The interesting thing is that the misfire seems to happen primarily under high load and higher RPM, especially in the higher gears. The CEL will flash when the misfire occurs, but it doesn�t stay on solid.
So far, I have tried:
Swapped the #2 ignition coil with #3 misfire stayed on cylinder 2.
Swapped the #2 spark plug with #3 misfire stayed on cylinder 2.
Swapped the #2 fuel injector with #3 misfire still stayed on cylinder 2.
Checked the spark plug and coil, and nothing obvious looked wrong.
Misfire counters show cylinder 2 as the highest, with the highest count I have seen around 48.
The car can be driven normally without the CEL flashing.
I can do a hard pull in 1st gear without triggering the flashing CEL, but the misfire tends to happen under higher load/higher speed in the higher gears.
I also notice the engine/exhaust sound changes noticeably around 5,000 RPM, almost like a late VarioCam switchover sound.
I also have P0420 and P0430 catalyst efficiency codes. The car has a Top Gear 200-cell X-pipe setup and I�m wondering if the exhaust setup could be contributing to the issue, although I realize it probably wouldn�t explain a consistent P0302.
At this point, since the misfire stayed on cylinder 2 after swapping the coil, spark plug, and injector, I�m starting to wonder if I�m dealing with:
Wiring or connector issue to cylinder 2 injector or coil
Vacuum/intake leak affecting cylinder 2
Mechanical issue such as compression or leak-down problem
Valve/spring issue that only shows up at high RPM
VarioCam-related issue
Fuel delivery issue under high load
Something related to the 200-cell cats/X-pipe or exhaust flow
The car has about 100k miles. The engine had a new updated short block installed around 66k miles.
What would you guys check next? Would you go straight to a compression and leak-down test, or is there another test I should do first to narrow this down?
Any advice from anyone who has dealt with a 996 M96 that only misfires on one cylinder at high RPM/load would be greatly appreciated.
With what you have already ruled out and your symptoms of the code setting on higher RPM and Load, I would pull the valve cover and check the valve springs for breakage, and inspect the lifters for damage....and inspect the cam lobes
I think one of those three are causing your problem...
So, your new mufflers were restricting exhaust flow ? How weird..
And were causing a consistent misfire on cylinder 2 ? Even more unbelievable..!!
I hope it stays fixed for your sake...
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