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Sources of low O2 circuit voltage

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6 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW

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YOUR RESEARCHSources of low O2 circuit voltage

Leading reported evidence

Check intake vacuum leak

Suggestion or failed attempt

No successful repair reported for this finding.

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Suggestion

Also check for intake vacuum leak.

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Sources of low O2 circuit voltage
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Leading evidence: 'Check intake vacuum leak' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Check intake vacuum leak' (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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1 matching discussions · 6 captured posts examined · 0 partial discussions

Frequently discussed actions (1)

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Check intake vacuum leak

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

Also check for intake vacuum leak.

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Sources of low O2 circuit voltage
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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.

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.

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Generation: 20261026T124918Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources

POST 1 / ORIGINAL POSTEROriginal post

All four of my O2 sensors indicate low voltage. To me this indicates an air leak after the MAF sensor. What is a good way other than going to the dealer to find the source?

POST 2Original post

Any CEL or pending error codes? It's not normal for the O2 sensors to have low voltage constantly. The DME should add fuel to compensate. What are the fuel trims?

POST 3 / ORIGINAL POSTEROriginal post

Cel is on. Codes are PO131,P0137,PO151 and PO 157.

POST 4Original post

Those codes are complaining all 4 sensors are shorted to ground (very unlikey). Do you have Durametric or other scanners that can display O2 sensor voltage readings in real-time? If you do, you can monitor those and see how the O2 sensors behave (to see if they are shorted like 0v or are still operating somewhat). Can also monitor the MAF and fuel trims reading. Could be a bad MAF (under reporting). Also check for intake vacuum leak.

POST 5Original post

To check air leak, you can spray brake cleaner onto suspected areas while engine is idling and note any change in engine idling speed (you can hear it). Just be careful not to spray on any exhaust/hot components.

POST 6 / ORIGINAL POSTEROriginal post

Don't have a real time capable scanner. Will try the brake cleaner. Thank you.

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