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2002 LEXUS GS 430
4.3L V8•RWD•AUTOMATIC•gas
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Repairs0Labor478Torque3074Fluid8DTC967Battery1Maintenance0Recalls0
P0138moderate severityPowertrain

O2 Sensor Circuit High Voltage Bank 1 Sensor 2

on 2002 Lexus GS 430 4.3L V8 · RWD

What this code means

The downstream O2 sensor on Bank 1 is reading high voltage consistently.

Symptoms

  • Check Engine Light
  • Failed emissions
  • May indicate catalyst failure

Common causes

  • Faulty sensor
  • Catalytic converter failure
  • Rich running condition

Diagnostic steps

  1. Test sensor voltage
  2. Check catalyst efficiency
  3. Monitor upstream vs downstream O2 patterns

Repair notes

Replace sensor. If catalyst failed, replace catalytic converter.

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