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1998 TOYOTA 4RUNNER
3.4L V6•4WD•AUTOMATIC•gas
4 active safety recalls on this vehicle — view recalls
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Repairs0Labor515Torque3482Fluid10DTC1663Battery1Maintenance0Recalls4
P0428moderate severityPowertrain

Catalyst Temperature Sensor High Input (Bank 1, Sensor 1)

on 1998 Toyota 4Runner 3.4L V6 · 4WD

What this code means

The PCM detected an abnormally high signal from the bank 1 catalyst temperature sensor. This may indicate a short to voltage or a failed sensor.

Symptoms

  • Check engine light on
  • Failed emissions test
  • High temperature reading

Common causes

  • Faulty temperature sensor
  • Short to voltage in wiring
  • Open ground circuit
  • Poor connector contact

Diagnostic steps

  1. Scan and confirm P0428
  2. Check sensor signal voltage
  3. Inspect wiring for shorts to power
  4. Test sensor resistance
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