P1139 — Subaru — Front Oxygen AF Sensor #1 Heater Circuit Performance Range Problem

P1139 (Subaru): Front Oxygen AF Sensor #1 Heater Circuit Performance Range Probl… — what it means, the affected system and what to check before replacing parts.

Meaning, symptoms, causes and checks

Front Oxygen AF Sensor #1 Heater Circuit Performance Range Problem. Source catalogue definition; confirm applicability using vehicle service information.

Affected system: Powertrain