Toyota 4Runner · Diagnostic Trouble Code
P0155 — O2 Sensor Heater Circuit Malfunction (Bank 2, Sensor 1)
Quick overview of P0155 on your Toyota 4Runner. Read the full diagnosis guide, then find the repair guides for your vehicle below.
Repair guides that fix P0155
General diagnostic information, not a factory service procedure. If you're unsure, have a qualified technician confirm the diagnosis before buying parts.