8 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCHP0430 & P0420 codes
Leading reported evidence
Use durametric
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 · Original poster
I've read through the various postings on the dreaded P0420/0430 fault codes, which I've recently observed using a Durametric on my 2000 C2 with 117K mi., and am somewhat confused, so asking for some help in distinguishing between O2 sensor failure and catalytic converter failure, or something else.
Leading evidence: 'Use durametric' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Use durametric' (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.
These are separate views of the same evidence. Frequency alone does not establish a fix, and these counts must not be added together.
Use durametric
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've read through the various postings on the dreaded P0420/0430 fault codes, which I've recently observed using a Durametric on my 2000 C2 with 117K mi., and am somewhat confused, so asking for some help in distinguishing between O2 sensor failure and catalytic converter failure, or something else.
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.
1 acknowledgements have no verified action link; they do not establish a repair result.
I've read through the various postings on the dreaded P0420/0430 fault codes, which I've recently observed using a Durametric on my 2000 C2 with 117K mi., and am somewhat confused, so asking for some help in distinguishing between O2 sensor failure and catalytic converter failure, or something else. (This is after the CEL came on a second time in ca. 200 miles, MAF sensor cleaned, and faults cleared). FWIW, Bank 1 sensor resistance was 128 behind vs. 64 ahead and 192 vs. 256, respectively, The following Bank 1 and Bank 2 sensor voltages, ahead vs. behind, were measured at 900 rpm idle on a hot engine:
It looks like your Bank 2 sensor are not reacting at ALL..
It's almost as if the wiring is switched........Double check that the wiring is going to the correct Sensor...
The second chart scale is too big to see the signal. These voltage reading are what I was seeing when I had the code. When the post cat O2 follows the pre cat sensor, the cats are toast. Mine did the same thing.
Thanks for the feedback. As a retired scientist also with old eyes, I'm embarrassed to see that the vertical scaling is off in the Bank 2 results, lol; will re-run and at a higher RPM. Previous posts listed various vendors, but some were no longer in business. Other than the Fabspeed cats, which looked to be the most viable non-OEM, can someone give me an updated list of possible vendors including re-builders? No need to pass emissions due to senior waiver in Maryland, but don't want anything much louder than OEM.
I went with the magnaflow cats because they are one of the few that are CARB compliant. No change in exhaust note. Later I bought an X-pipe with 200 cell cats from FSI. Very noticeable change in tenor of the exhaust, not louder. Maybe more exotic(?). There was also a noticeable change in throttle response. Butt dyno error bars apply.
Magnaflow says they don't have a cat for my 2000 996 C2, although part numbers for 2000 and 2001 are the same (99611303102) and they do list one for 2001 996. Rockauto has a
Davico
CARB-compliant one for much less, I wonder how risky that would be.
This is a source reference. Confirm exact model applicability in the original material.
