1995 Geo Prizm Base, AutomaticFACTORY OEM SERVICE PROCEDURE

Diagnostic Procedures

Verify clean, tight connection on G106 (Brown wire). An intermittent condition may be caused by poor connection, rubbed-through insulation, or a broken wire inside insulation. Check ECM harness connectors for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal-to-wire connections before component replacement.

Fig 1: DTC 27 Schematic (Prizm 1.6L VIN 6 - California Emissions), Sub-O2 Sensor (Sub-O2s), Open Or Shorted Ckt.
G95D31768
Factory Service Tools

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Pair factory procedures with proven DIY tools so the instructions are easier to execute.

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.