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O2 Sensor Questions

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5 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis

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YOUR RESEARCHO2 Sensor Questions

Leading reported evidence

Check connector pins coming

Suggestion or failed attempt

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Unsuccessful attempts: 1
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Suggestion
While disconnected, check connector pins coming from ecu for voltage or ground.
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O2 Sensor Questions

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Leading evidence: 'Check connector pins coming' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Check connector pins coming' (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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Check connectors

Suggestion or failed attempt

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Reported fixes: 0
Unsuccessful attempts: 1
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Suggestion
You might check the connectors to the sensors, unplug to see if the diagnostic tool registers the open circuit.
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O2 Sensor Questions

Replace 4

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Suggestion · Original poster
Or - is it easier to just replace all 4?
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O2 Sensor Questions

Run little lean or rich

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Unsuccessful attempts: 1
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Discussions that contain suggestions: 1

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Suggestion · Original poster
I fear the O2 sensors throwing codes is causing me to run a little lean or rich, which isn't ideal, obviously.
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O2 Sensor Questions

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 connector pins coming

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
While disconnected, check connector pins coming from ecu for voltage or ground.
Original post Read captured discussion
O2 Sensor Questions

Check connectors

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
You might check the connectors to the sensors, unplug to see if the diagnostic tool registers the open circuit.
Original post Read captured discussion
O2 Sensor Questions

Replace 4

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
Or - is it easier to just replace all 4?
Original post Read captured discussion
O2 Sensor Questions

Run little lean or rich

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 fear the O2 sensors throwing codes is causing me to run a little lean or rich, which isn't ideal, obviously.
Original post Read captured discussion
O2 Sensor Questions

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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.

5 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.

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Generation: 20261027T003124Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources

POST 1 / ORIGINAL POSTEROriginal post

Vehicle: 99 C2, Manual, Coupe, 130k miles On a drive the other morning, my check-engine light popped on and gave me codes for all four O2 sensors. The previous owner has a receipt and shows replacing two or both of the downstream O2 sensors, however (OEM Quality from Pelican). Because it's all four, I'm thinking that this isn't actually O2 sensors, but maybe a ground or electrical issue? If that's the case - how do I go about diagnosing it and addressing it? Or - is it easier to just replace all 4? I suppose it's common for these things to go bad. Pelican has a kit with the tool for ~$500 that doesn't seem too bad a job. Any thoughts here? I fear the O2 sensors throwing codes is causing me to run a little lean or rich, which isn't ideal, obviously. Any help is appreciated. Thanks!

POST 2Original post

First step is to get the Fault Codes... Second Step, if you want someone else to help you, is to Post the Fault Codes ...

POST 3 / ORIGINAL POSTEROriginal post

Ahh! You're right - I'm sorry. Fault Codes: P0131 P0151 P0157 P0137

POST 4Original post

This has to be bad power or ground to the o2. I would graph the sensors on a scanner to view the voltages. If u cant do that the plugs r acceccable by the air cleaner. U can back pin and teat them. U basicaly have to diag the system with a multimeter

POST 5Original post

I’d not buy new sensors just yet. Some readers like Durametric show graphs of voltage and resistances vs. time of each sensor and how they vary with engine on, you’d be able to see if the sensors are/aren’t working. You might check the connectors to the sensors, unplug to see if the diagnostic tool registers the open circuit. While disconnected, check connector pins coming from ecu for voltage or ground. (Electrical schematic will show which pins are which.) Amazon sells Bosch sensors for less, and the removal tool.

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