Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
1995 Cadillac Eldorado BaseFACTORY OEM SERVICE PROCEDURE
Code P042, Front Oxygen Sensor Lean Signal: Action
PCM turns on MIL. PCM turns on canister purge solenoid if Code P044 is also set. Transaxle shift adapts are maintained at current levels.
NOTE:
Test numbers refer to numbers on diagnostic chart.
- If Code P017 is present, diagnose this code first since an oxygen sensor not ready can cause other emission related problems.
- If oxygen sensor is operating correctly, voltage should fluctuate at greater than 0.3 volt. A lean sensor condition will cause voltage to remain at less than 0.3 volt.
- If voltage measured is greater than 0.15 volt, PCM and circuit No. 412 are okay.
Factory Service Tools
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.