AIR Fuel Ratio

1999 Chevrolet Lumina V6-3.8L VIN KSECTION AIR Fuel Ratio
Scan Tool Range 0.0 to 25.5. Air Fuel Ratio indicates the PCM commanded ratio of Air to Fuel. In closed loop, the Air Fuel Ratio should normally be around 14.2 - 14.7. A lower Air Fuel Ratio indicates a richer commanded mixture, which may be seen during Power Enrichment or TWC Protection modes. A higher Air Fuel Ratio indicates a leaner commanded mixture. This can be seen during Decel Fuel Mode.
RENDER: 1.0x

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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.