6 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCHCEL code p0420
Reported or suspected cause
converter(s)
Suggestion or failed attempt
No successful repair reported for this finding.
0
Identified cause
1
Suspected cause
0
Reported fixes
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 suspect a cause
1
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Suspected cause
My info is if the P0420 (or P0430) code not accompanied by any aging O2 sensor codes the problem is with the converter(s).
Leading evidence: 'converter(s)' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, the most frequently mentioned possible cause is 'converter(s)' (1 discussions; 0 report identifying it and 1 suggest it). The most frequently discussed action is 'Check throttle body' (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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Discussions that contain suggestions
1
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Suggestion
You can check the throttle body to see if it requires cleaning.
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.
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Suggestion · Original poster
02 996 c2 with 88k miles on body (and exhaust system) and ~7k miles on new engine so maf has 7k miles on it and so does the air filter and throttle body (possible I need to clean any of those?!)
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.
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Suggestion
Furthermore, my inf is if there are O2 sensor aging code(s) the recommended procedure is to replace the O2 sensor(s) and clear the codes and drive the car to see if the P0420/P0430 codes reappear.
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.
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
02 996 c2 with 88k miles on body (and exhaust system) and ~7k miles on new engine so maf has 7k miles on it and so does the air filter and throttle body (possible I need to clean any of those?!)
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
Furthermore, my inf is if there are O2 sensor aging code(s) the recommended procedure is to replace the O2 sensor(s) and clear the codes and drive the car to see if the P0420/P0430 codes reappear.
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.
6 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: 20261027T000231Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources
Steady CEL came on during the commute to work this AM. Durameteric shows its P0420. Search here is not conclusive - either O2 or the cat itself.
How do I test to see which it is? Can it all be done using the durametric or will I need to remove/unplug any O2 sensor?
what side of the car is bank 1?
02 996 c2 with 88k miles on body (and exhaust system) and ~7k miles on new engine so maf has 7k miles on it and so does the air filter and throttle body (possible I need to clean any of those?!)
Thanks
My info is if the P0420 (or P0430) code not accompanied by any aging O2 sensor codes the problem is with the converter(s).
Furthermore, my inf is if there are O2 sensor aging code(s) the recommended procedure is to replace the O2 sensor(s) and clear the codes and drive the car to see if the P0420/P0430 codes reappear.
You can check the throttle body to see if it requires cleaning. It may be a bit gunky with oil from the AOS. This does not mean the AOS is bad just that due to the proximity of the AOS hose to the intake manifold oil vapors over time can foul the throttle body. Won't help the P0420 code though. But you'll feel better eliminating the TB is my guess.
My 02 Boxster has been emitting a P0430 code now for over 2 years, off and on, sometimes every couple of weeks and in warmer weather sometimes not for several months. I'm not replacing the converter(s) until I have to to get the car to pass smog. So far it has passed, but the margin is shrinking. And last time just a while after the smog test the CEL came on. Good old P0430.
Sincerely,
Macster.
Thanks Macster. I'll be honest, I called code brown when it came on (images of an IMS failure in my head) but didnt feel any difference in idle or see any smoke and everything seemed ok so I just continued to work and read up that a steady light is ok to drive on.
is there a way to test the o2 sensors? i have a durametric if that helps....
edit : idle and 3k rpm durametric screen shots - can anyone translate? the number change a lot so this may be futile...
PasPar2, if you pm me with your email address I can send you excel data sheets and charts, showing how to set up the Durametric and what to diagnose. I've done this with both good and bad cats.
