211
UnclassifiedGeneral
What This Code Means
DST displays HO2S voltage fixed below 0.35 after 2 minutes of run time; Lean exhaust condition at light load; False lean condition; Intermittent problem
Possible Causes
- •Exhaust leak pulling outside air past O2 sensor
- •Faulty ECM grounds
- •Faulty HO2S sensor
- •Fuel system operating out of specification
- •Large vacuum leaks
- •Oxygen sensor wires mispositioned and contacting exhaust (short to ground between harness and sensor or on sensor harness)
Suggested Actions
- 1Check and adjust fuel system according to PSI guidelines
- 2Check for exhaust leaks
- 3Check for short to ground between harness and sensor and on sensor harness
- 4Check for vacuum leaks
- 5If any other DTCs are present, diagnose those first
- 6If fuel system is operating to specification, replace HO2S sensor with a known good part and retest
- 7Verify ECM grounds are good battery or engine grounds
- 8Warm engine to normal operating temperature by idling for a minimum of 2 minutes
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