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Home >> Geo >> 1993 >> Prizm Base, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Tests W/Codes >> (VIN 8) CODE CHARTS (PRIZM LSi) >> Code 26, O2 Sensor CKT, Rich Exhaust Indicated >> Diagnostic Aids
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Diagnostic Aids

Verify clean, tight connection on G106 (Brown wire). A rich air/fuel condition may be caused by high fuel pressure, faulty EVAP canister purge system, faulty MAP sensor, or faulty EGR system (Calif. emissions only).

An intermittent condition may be caused by poor connection, rubbed-through insulation, or a broken wire inside insulation. Check PCM harness connectors for backed-out, improperly mated, broken locks, improperly formed, or damaged terminals, and poor terminal-to-wire connections before component replacement.

Fig 1: Code 26 Schematic (LSi) Oxygen Sensor Circuit, Lean Exhaust Indicated
G93C79121
Fig 2: Code 26 Flow Chart (LSi) Oxygen Sensor Circuit, Lean Exhaust Indicated
G93D79122