P1155low severityPowertrain

Air/Fuel Sensor Heater Circuit Bank 1 Sensor 2

on 2000 Toyota 4Runner 3.0L V6 · 4WD

What this code means

Heater circuit fault in the downstream A/F sensor.

Symptoms

  • CEL
  • Poor cold-start economy
  • Increased warm-up emissions

Common causes

  • Failed heater element
  • Open wiring
  • Blown fuse
  • Corroded connector

Diagnostic steps

  1. Test heater resistance
  2. Check fuse
  3. Inspect wiring

Repair notes

Replace sensor or repair heater circuit.

Other Powertrain codes on this vehicle

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