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2001 GMC SAVANA
4.3L V6•RWD•gas•L35
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Repairs0Labor505Torque139Fluid8DTC1763Battery1Maintenance0Recalls0
P1135moderate severityPowertrain

HO2S Lean Mean Bank 1 Sensor 1

on 2001 GMC Savana 4.3L V6 · RWD

What this code means

The bank 1 upstream oxygen sensor reports a consistently lean average. The engine may be running with too much air or too little fuel.

Symptoms

  • Check engine light on
  • Lean running
  • Hesitation or misfire

Common causes

  • Vacuum or intake leak
  • Faulty O2 sensor
  • Low fuel pressure
  • Dirty MAF sensor

Diagnostic steps

  1. Scan and check fuel trims
  2. Inspect for vacuum leaks
  3. Test fuel pressure
  4. Verify O2 sensor operation
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