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Home >> Oldsmobile >> 1991 >> Custom Cruiser >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Engine Controls - Tests W/Codes - 5.7L TBI >> Diagnostic Flow Charts For Codes: 13 To 55 >> Code 45, Rich Exhaust Indication >> O2 Sensor Contamination
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O2 Sensor Contamination

O2 sensor contamination, caused by silicone in certain fuels or use of improper RTV sealant, may cause a White powdery coating to cover the exterior of the O2 sensor. The false high signal voltage (low oxygen content sensed) produced is interpreted by the control module as a rich mixture, causing the control module to set Code 45.