Code 44, Lean Exhaust Indication - All Models: Notes

1995 GMC Forward Control 4.3 Z, StandardSECTION Notes

Sensor acts like an open sensor circuit and produces no voltage when exhaust temperature is less than 600°F (316°C). An open sensor circuit or cold sensor causes "open loop" operation.

NOTE: Test numbers refer to test numbers on diagnostic chart.
  1. Code 44 sets when O2 sensor signal remains low for a precalibrated period and system is operating in "closed loop".
RENDER: 1.0x

NO RELATED

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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.